Computer Sciences – 2022

Assistant Lecturer

Jamal Ali Hammad

University of Anbar College of Pharmacy

2021 - 2022

List of Contents

Page No.

Chapter One Computer Basics

2 1. Introduction

2 2. Computer Science

2 3. Basics of Computer

3 3.1 What is a Computer?

3 3.2 Functions of Computer

6 3.3 Data and Information

7 3.4 History of Computers

10 3.5 Characteristics of Computer System

11 3.6 Basic Applications of Computer

16 4. Computer Classification

20 5. Components of Computer System

20 5.1 Computer Hardware

42 5.2 Computer Software

45 6. Computer Numbering Systems

49 7. Programming Languages

51 8. Information Technology

Chapter Two

Computer Networks

55 1. Computer Network

60 2. Internet

62 3. Web Browsing Software

66 4. E- Mail

Chapter Three

Computer Viruses and Crimes

67 1. Computer Viruses

69 2. Computer Crimes

70 Chapter Four

Getting Started with Windows

96 Chapter Five

Working with Files

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https://www.tutorialspoint.com/computer_concepts/computer_concepts_characteristics_of_computer_system.htm

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Computer Sciences – 2022 Jamal Ali Hammad

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Chapter One

Computer Basics


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1. Introduction

Computer Science is one of the disciplines of modern science under which, we

study about the various aspects of computer technologies, their development, and their

applications in the present world. Computer Science includes a wide range of topics such

as the software engineering, networking, artificial intelligence, development of Computer

Technology (hardware and software), applications of Computer in today‟s life, information

technology, computer threat, computer security, etc. However, we have segregated this

tutorial into different chapters for easy understanding.

Our Computer sciences tutorial includes all topics of Computer fundamentals such as input

devices, output devices, memory, CPU, motherboard, computer network, virus, software,

hardware etc.

2. Computer Science The science that deals with the theory and methods of processing information in

digital computers, the design of computer hardware and software, and the applications of

computers. The discipline of computer science includes the study of algorithms and data

structures, computer and network design, modeling data and information processes, and

artificial intelligence. Computer science draws some of its foundations from mathematics

and engineering and therefore incorporates techniques from areas such as queuing theory,

probability and statistics, and electronic circuit design. Computer science also makes heavy

use of hypothesis testing and experimentation during the conceptualization, design,

measurement, and refinement of new algorithms, information structures, and computer

architectures.

An algorithm is a detailed and unambiguous sequence of actions for solving a

problem or for performing some task. Algorithms are essential to the way computers

process information because a computer program is basically just an algorithm that tells

the computer what specific steps to perform (and in what sequence) in order to carry out a

specified task. Principal areas of study within Computer Science include artificial

intelligence, computer systems and networks, security, database systems, human computer

interaction, vision and graphics, numerical analysis, programming languages, software

engineering, bioinformatics and theory of computing.

3. Basics of Computer In today's world, we use computers for all our tasks. Our day-to-day activities:

paying bills, buying groceries, using social media, seeking entertainment, working from

home, communicating with a friend, etc., can all be done using a computer. So, it is

important not only to know how to use a computer, but also to understand the components

of a computer and what they do.

This topic explains all concepts related to computer in detail, from origin to end.

The idea of computer literacy is also discussed, which includes the definition and

functions of a computer and learn about the components of a computer, the concept of

hardware and software, representation of data/information, the concept of data processing

and applications of Information.

http://www.linfo.org/program.html

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3.1 What is a Computer?

A computer is a programmable electronic device that accepts raw data as input

and processes it with a set of instructions (a program) to produce the result as output, it

renders output just after performing mathematical and logical operations and can save the

output for future use. It can process numerical as well as non-numerical calculations. The

term "computer" is derived from the Latin word "computare" which means to calculate.

A computer is designed to execute applications and provides a variety of solutions

through integrated hardware and software components. It works with the help of programs

and represents the decimal numbers through a string of binary digits. It also has a memory

that stores the data, programs, and result of processing. The components of a computer

such as machinery that includes wires, transistors, circuits, hard disk are called hardware.

Whereas, the programs and data are called software.

Computer

3.2 Functions of Computer

There are necessary functions of computer that needs to perform by the computer

itself for completing all the task. Not every PC owner knows about the specific functions

the corresponding computing device performs. Basically, a computer is an electronic

machine, used for processing and storing, the data given by the user. There are different

types of computers from micro to supercomputers. Some have many functions with

complexity while the basic computer has only 4 functions. So, this article explains the

basic functionality of the computer system as well as the functions of each component.

In the most general sense, The Four Basic Functions of Computers are: –

1. Input Function

2. Processing Data

3. Data Storage

4. Output Function

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Functions of Computer

Let‟s understand all the 4 Basic functions of computer easily, be with me:

1. Input Function

Input is the process of entering any type of data and instructions into a computer

system by using the input devices such as a Keyboard, Mouse, Scanner, Microphone, etc,

in order to receive user signals to the computer. We use such input devices to input the

data into the computer by typing the words and sentences through the keyboard, by

scrolling and clicking the buttons through the mouse, recording the audio and video

through microphone and camera, etc.

By using these input devices, we can perform the basic tasks in computer-like calculations,

viewing the images and videos, listening to the audios, preparing the PPT documents,

browsing the Internet. In fact, all the basic functions of a computer user are initiated by

inputting the data into the computer through input devices.


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2. Processing Data

This processing function is the 2nd step that offers the process and handling of the

input data instructed by the user. To process the user input data computer needs a‟ Central

Processing Unit„ (CPU). The computer CPU, of course, is primarily obliged to entire

process data of the computer. The CPU takes data and instructions from the input devices

and performs all types of calculations based on the instructions given.

It consists of manipulating the data in different ways, performing calculations, modifying

the instructions, coding, and executing the actions. All this process is done on the

motherboard with the help of the processor, power supply unit and RAM presented in the

CPU.

3. Data Storage

The computer must store the data permanently so that it is available while

processing data temporarily. The function of data storage is an important component for

the proper functioning of computer systems. Basically, there are two types of storage in the

CPU of a Computer – One is RAM (used for processing the input data temporarily )

and the second is ROM (used to store processed data permanently).

4. Output Function

The fourth and last function of the computer is the output that means the results

generated by the computer once the processing of CPU is completed, based on the

instruction given by the user. The output is in the form of documents, videos, audio, graphs,

images, etc. that you see from the output devices such as computer monitor, printer,

speakers, headphones, screen projector, etc. Thus, now all the results are displayed on your

computer screen.

The above all are the basic and significant functions of computers for completing everyday

tasks from simple tasks like word processing, paint, recording videos PPT to complicated

tasks like playing games, videos, graphic designing, etc. The process of moving data

between a computer and the external components of the computer is called the I/O process

is done I/O Devices.

In Simple Words, the working of a computer mainly :

Step 1. Accepting the data from Input Devices – Like Keyboard, Mouse, Microphone.

Step 2. Transfer data to RAM memory in the CPU.

Step 3. Processing. Analyzing and Storing the data as per instructions.

Step 4. At last, after the process sending the results to the Output Devices – Like Monitor,

Printer, Speakers.

In short, The information and data are given to computers using Input devices in a discrete

form. The input device accepts and transfers the data to the CPU. After that, the data is

handled or processed by the CPU and stored in the Memory of the Computer. And in this

way, we get the output results of our instructions through Output Devices.

https://www.brainkart.com/article/Input-Output-Devices-for-Discrete-Data_6395/

https://www.brainkart.com/article/Input-Output-Devices-for-Discrete-Data_6395/


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3.3 Data and Information

Data is a collection of unorganized facts and figures and does not provide any further

information regarding patterns, context, etc. Hence data means "unstructured facts and

figures".

Information is a structured data i.e., organized meaningful and processed data. To

process the data and convert into information, a computer is used.


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3.4 History of Computers

This development period of electronic computing technology is called Computer

Generation. Computer generations are based on when major technological changes in

computers occurred, like the use of vacuum tubes, transistors, and the microprocessor. As

of 2020, there are five generations of the computer, although the sixth generation could be

in development now in the early 21st century. During the evolutionary timeline, each

generation of computers has improved a lot by undergoing considerable changes in their

size, type, and functionality.

By analyzing them, one can trace the evolution of computer technology, to see how

the computer industry has changed over the years and how great capabilities and software

progress has been made by humankind in under a hundred years, as a result, the creation of

different generations.

At present, the computer is playing a significant part in human existence because

today‟s digital computer is being used for every work in each field. If someday an issue

occurs in the computer or the server is down, at that point all the work stops. This is how

significant it is for technology development!

The brief history of computers is discussed in the next page.

1. First Generation (1940 - 1956)

The first generation of computers used vacuum tubes as a major piece of

technology. Vacuum tubes were widely used in computers from 1940 through 1956.

Vacuum tubes were larger components and resulted in first generation computers being

quite large in size, taking up a lot of space in a room. Some of the first-generation

computers took up an entire room.

The ENIAC is a great example of a first-generation computer. It consisted of nearly 20,000

vacuum tubes, as well as 10,000 capacitors and 70,000 resistors. It weighed over 30 tons

and took up a lot of space, requiring a large room to house it. Other examples of first

generation computers include the EDSAC, IBM 701, and Manchester Mark 1.

Vacuum tubes

https://www.tutorialspoint.com/computer_concepts/computer_concepts_history_of_computers.htm

https://www.computerhope.com/jargon/v/vacuumtu.htm

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https://www.computerhope.com/history/1956.htm

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2. Second Generation (1956 - 1963)

The second generation of computers saw the use of transistors instead of vacuum

tubes. Transistors were widely used in computers from 1956 to 1963. Transistors were

smaller than vacuum tubes and allowed computers to be smaller in size, faster in speed,

and cheaper to build. The first computer to use transistors was the TX-0 and was

introduced in 1956. Other computers that used transistors include the IBM 7070, Philco

Transac S-1000, and RCA 501.

Transistors

3. Third Generation (1964 - 1971)

The third generation of computers introduced the use of IC (integrated circuits) in

computers. Using IC's in computers helped reduce the size of computers even more

compared to second-generation computers, as well as make them faster.

Nearly all computers since the mid to late 1960s have utilized IC's. While the third

generation is considered by many people to have spanned from 1964 to 1971, IC's are still

used in computers today. Over 45 years later, today's computers have deep roots going

back to the third generation.

Integrated circuits


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4. Fourth Generation (1972-2010)

The fourth generation of computers took advantage of the invention of the

microprocessor, more commonly known as a CPU. Microprocessors, along with

integrated circuits, helped make it possible for computers to fit easily on a desk and for

the introduction of the laptop. Some of the earliest computers to use a microprocessor

include the Altair 8800, IBM 5100, and Micral. Today's computers still use a

microprocessor, despite the fourth generation being considered to have ended in 2010.

Microprocessor

5. Fifth Generation (2010-Present)

The fifth generation of computers is beginning to use AI (artificial intelligence),

an exciting technology that has many potential applications around the world. Leaps have

been made in AI technology and computers, but there is still room for much improvement.

One of the more well-known examples of AI in computers is IBM's Watson, which was

featured on the TV show Jeopardy as a contestant. Other better-known examples include

Apple's Siri on the iPhone and Microsoft's Cortana on Windows 8 and Windows 10

computers. The Google search engine also utilizes AI to process user searches.

Robots


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3.5 Characteristics of Computer System

The characteristics of the computer system are as follows −

2.4.1 Speed

A computer works with much higher speed and accuracy compared to humans

while performing mathematical calculations. Computers can process millions

(1,000,000) of instructions per second. The time taken by computers for their

operations is microseconds and nanoseconds.

2.4.2 Accuracy

Computers perform calculations with 100% accuracy. Errors may occur due to

data inconsistency or inaccuracy.

2.4.3 Diligence

A computer can perform millions of tasks or calculations with the same

consistency and accuracy. It doesn‟t feel any fatigue or lack of concentration. Its

memory also makes it superior to that of human beings.

2.4.4 Versatility

Versatility refers to the capability of a computer to perform different kinds of

works with same accuracy and efficiency.

2.4.5 Reliability

A computer is reliable as it gives consistent result for similar set of data i.e., if

we give same set of input any number of times, we will get the same result.

2.4.6 Automation

Computer performs all the tasks automatically i.e., it performs tasks without

manual intervention.

2.4.7 Memory

A computer has built-in memory called primary memory where it stores data.

Secondary storage are removable devices such as CDs, pen drives, etc., which are also

used to store data.

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3.6 Basic Applications of Computer

Computers are playing a vital role in almost every field and making our day-to-day

tasks more manageable. Computers were only used to perform complex numerical

calculations in a previous time, but they have reached too far and now perform many

different roles. They are now performing diverse set functions from complicated

calculations to generating business reports, bill generation to education, programming or

development to entertainment, etc.

Because of their characteristics and powerful functionalities, computers are used in various

fields, such as homes, businesses, government offices, research organizations, educational

institutions, medical, entertainment, etc. Computers have taken industries and businesses to

a whole new level. In this article, we have elaborated the most common uses of computers

in different fields:


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2.5.1 Business

Currently, computers can be seen in almost every business. Computers are almost

part of a business setup because they increase productivity and help race in a competitive

environment. In businesses, computers are primarily used to store and manage accounts

and personal data, maintain projects, track inventory status, and make reports and

presentations. Besides, computers are best suited for transaction processing because they

are more accurate and faster than humans. Computers also help people analyze their

investment, expenses, profits, sales and many other aspects of the business.

2.5.2 Science

Scientists are amongst one of those people who use computers as their primary

work tool. In science, research and engineering, computers are best suited for collecting,

analyzing, categorizing, and storing the data. They also help scientists to exchange data

with each other both internally and internationally. Computers enable scientists from

different locations (such as different countries) to work together on the same project with

cloud support. Besides, computers play a crucial role in launching, maintaining, controlling

spacecraft, and operating many other technologies.

2.5.3 Government

In the government sector, computers are beneficial. They are getting used to

performing various functions in different departments and improving their services'

quality, efficiency, and productivity. Some examples of such services are city planning,

traffic control, law enforcement, infrastructure developments, and tourism. In most cases,

the primary purposes of using computers are performing data processing tasks, maintaining

citizens' database, and promoting a paperless environment. Apart from this, computers are

playing a crucial role in the country's defense system. They are helping in missile

development, rocket, satellite launches, etc.

2.5.4 Health and Medical

Computers are radically changing the methods of diagnosis in hospitals. They are

used for maintaining patients' information, records, live monitoring of patients, X-rays, and

more. Everything is being digitized with the help of computers. Computers help configure

lab-tools, monitor heart rate, and blood pressure, etc. Doctors get extra advantages in

treating patients with proper drugs and medicines. Additionally, computers enable doctors

to exchange patient's data easily with other medical specialists. Besides, advanced surgical

devices are based on robotics that helping surgeons to conduct complex operations and

surgeries remotely.


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2.5.5 Education

Computers are broadly getting used in the education field. They help people get

different educational materials (such as images, videos, e-books, etc.) in one place. All

such information can be accessed through the Internet. Additionally, computers are best

suited for online classes, online tutoring, online examinations, and creating assignments

and projects. Apart from this, they can also be used to maintain and monitor student

performance and other information.

2.5.6 Industry

Computers are used in industries to perform various tasks, such as maintaining inventory,

interior designing, designing samples or virtual products, communicating over video

conferencing, and more. Online marketing has made it easier for people to buy products in

rural areas. Online trading in stock markets has also seen a significant revolution due to its

easy participation potential. Computers have enabled people from different levels of

different locations to participate easily in stock marketing.

2.5.7 Banking

Banking has become so advanced in the past few years. Most countries use online

banking systems where customers can access their data directly using computers and the

Internet. People can check their account balance, transfer money, and pay online bills,

including credit cards. Besides, Banks use computers to perform transactions and store

customer data, transaction records, etc. Banks have reduced the number of manual errors,

number of employees, and costs to a great extent by using computers. ATMs are the best

example of computers that are helping people to withdraw and deposit the money

themselves.

2.5.8 Entertainment

Computers nowadays are one of the best mediums for entertainment. Computers

can be used to watch movies, play games, listen to music, etc. Computers combined with

MIDI instruments can be used to record audio through artificial instruments. Besides,

people can also enjoy recording their videos with webcam and apply several entertaining

AI effects. Several Photo editor programs are also available with fabulous powerful

features.


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2.5.9 Training

Most companies use computers to provide training to their employees. Computer-based

training helps companies save their time, money, and increase productivity. Also,

computer-based training can be used to train employees for large distances in various

locations. This will eliminate travel time and costs, making the training process much more

comfortable and smoother.

2.5.10 Arts

Computers have become part of art, photography, dance, and culture. Computers

with advanced features allow users to draw their projects directly on it. Besides, people can

use computers to digitize their photos. There are several photo editor software that can help

people edit and customize their photos. Apart from this, the dance's movements and steps

can be shown live with animations' help.

2.5.11 Sports

In today's technologically developed world, computers are being used in almost

every sport. There are many sports activities where computers are making things possible.

In sports, computers are mainly used to maintain scoreboards, records, and other statistics.

Furthermore, they are used to analyze player movements and make various in-game

decisions. Computers help make complex in-game decisions (especially in umpiring),

which cannot be seen by human eyes.

2.5.12 Robotics

Robotics is one of the emerging fields of technology that uses computers for

science and engineering as well as designing machines. These machines can be virtual

(such as software bots) and physical ones that can reduce or eliminate human workload.

Additionally, some machines can perform heavy tasks that humans cannot complete, or

that may take a long time to complete. Car manufacturing was one of the first examples

where robots helped to assemble car parts and perform many other heavy tasks. However,

nowadays, robots are beneficial in many fields, such as exploring areas where conditions

are difficult for humans, helping the military, helping law enforcement and helping health

professionals, etc.


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2.5.13 Safety and Security

Computers are capable of working together with different equipment, tools, and

technologies. When it comes to safety, computers are widely being used with the security

camera. Almost every private and government organizations are equipped with security

cameras to monitor people and goods. Also, these cameras are helping security intelligence

agencies to identify terrorists or criminals in public places. Computers attached with a

fingerprint scanner and face-recognition technology have made it harder for fraudsters to

use fake identities and take government benefits using someone else's identity. Security

systems have become so powerful with the introduction of computer technology and the

Internet.

2.5.14 Publishing

Computers are one of the first choices when it comes to publication. Computers are mainly

used for designing newsletters, novels, posters, magazines, or newspapers, etc. They are

suitable for almost every type of publication. Computers can be seen in both types of

publishing methods, either its hard-copy or e-books. Apart from this, computers play a

vital role in blogging and writing articles on websites.

2.5.15 Weather Forecasting

Weather forecasting is never easy for humans because it depends on many factors that are

continually changing. It is almost impossible for humans to predict the weather without

using a computer. The weather forecasting process involves complex computation and

monitoring of data from satellites and many other technological devices. The computer has

made it a little easier to predict weather conditions because it can process information from

different sources and make complex calculations related to it, which are necessary for

forecasting. Computers process enormous amounts of meteorological information during

weather forecasting.

2.5.16 Communication

Computers have become one of the primary sources of communication. Modern computers

come with a built-in webcam and microphone to make use of communication easier.

People can use software like Skype and Hangout to connect with other people over the

Internet. Because of the videoconferencing feature, people can connect with audio and

video. Computers help families connect to their relatives, businesses to organize meetings,

and companies to take interviews, between two different locations that are too far. Apart

from this, older communications methods such as emails are also still used widely.


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4. Computer Classification

Historically computers were classified according to processor types because

development in processor and processing speeds were the developmental benchmarks.

Earliest computers used vacuum tubes for processing, were huge and broke down

frequently. However, as vacuum tubes were replaced by transistors and then chips, their

size decreased and processing speeds increased manifold.

All modern computers and computing devices use microprocessors whose speeds and

storage capacities are skyrocketing day by day. The developmental benchmark for

computers is now their size. Computers are now classified on the basis of their use or size

Desktop

Laptop

Tablet

Server

Mainframe

Supercomputer

Let us look at all these types of computers in detail.

1. Desktop

Desktop computers are personal computers (PCs) designed for use by an

individual at a fixed location. IBM was the first computer to introduce and popularize use

of desktops. A desktop unit typically has a CPU (Central Processing Unit), monitor,

keyboard and mouse. Introduction of desktops popularized use of computers among

common people as it was compact and affordable.

Personal Computer

Riding on the wave of desktop‟s popularity many software and hardware devices were

developed specially for the home or office user. The foremost design consideration here

was user friendliness.


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2. Laptop

Despite its huge popularity, desktops gave way to a more compact and portable personal

computer called laptop in 2000s. Laptops are also called notebook computers or

simply notebooks. Laptops run using batteries and connect to networks using Wi-Fi

(Wireless Fidelity) chips. They also have chips for energy efficiency so that they can

conserve power whenever possible and have a longer life.

Modern laptops have enough processing power and storage capacity to be used for all

office work, website designing, software development and even audio/video editing.

3. Tablet

After laptops computers were further miniaturized to develop machines that have

processing power of a desktop but are small enough to be held in one‟s palm. Tablets

have touch sensitive screen of typically 5 to 10 inches where one finger is used to touch

icons and invoke applications.

Keyboard is also displayed virtually whenever required and used with touch strokes.

Applications that run on tablets are called apps. They use operating systems by Microsoft

(Windows 8 and later versions) or Google (Android). Apple computers have developed

their own tablet called iPad which uses a proprietary OS called iOS.


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4. Server

Servers are computers with high processing speeds that provide one or more services to

other systems on the network. They may or may not have screens attached to them. A

group of computers or digital devices connected together to share resources is called

a network.

Servers have high processing powers and can handle multiple requests simultaneously.

Most commonly found servers on networks include −

File or storage server

Game server

Application server

Database server

Mail server

Print server

5. Mainframe

Mainframes are computers used by organizations like banks, airlines and railways to

handle millions and trillions of online transactions per second. Important features of

mainframes are −

Big in size

Hundreds times Faster than servers, typically hundred megabytes per second

Very expensive

Use proprietary OS provided by the manufacturers

In-built hardware, software and firmware security features


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6. Supercomputer

Supercomputers are the fastest computers on Earth. They are used for carrying out

complex, fast and time intensive calculations for scientific and engineering applications.

Most common uses of supercomputers include −

Molecular mapping and research

Weather forecasting

Environmental research

Oil and gas exploration


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5. Components of Computer system

Every computer is composed of two basic components: Hardware and Software.

1. Computer hardware is the umbrella term used to describe the physical collection of

elements that complete a whole computer system. Hardware encompasses the external

tools that allow users to operate a computer, such as the keyboard, mouse and the

monitor, and internal components like the motherboard, graphics card, and hard disc.

2. Computer software is the term used to define the sets of code, data, and instructions

stored on the computer‟s hard drive that operate the machine from behind the scenes.

In other words, software allows a computer to actually perform tasks, without

software, computer hardware would be entirely useless.

5.1 Computer Hardware

The term 'Computer hardware' or 'Computer parts' is used to describe the

physical and tangible components of a computer, i.e. the components that can be seen and

touched. The components that make up hardware can be categorized as being either

internal or external. Internal components are those installed inside the computer, typical

examples being the motherboard, power supply, and central processing unit (CPU).

External components are connected to the outside of the computer, these can also be

referred to as peripherals, or peripheral devices, common examples being the monitor,

keyboard, and mouse.

There are 4 main Computer Hardware components that are given below:

A. Input devices − keyboard, mouse, etc.

B. Output devices − printer, monitor, etc.

C. Processing Devices – Central Process Unit.

D. Computer Memory – RAM, ROM, etc.

E. Other Components of Computer Hardware – Motherboard.


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Computer hardware

The operations of computer hardware components are given below:

1. Inputting: It is the process of entering raw data, instructions and information into the

computer. It is performed with the help of input devices.

2. Storing: The computer has primary memory and secondary storage to store data and

instructions. It stores the data before sending it to CPU for processing and also stores

the processed data before displaying it as output.

3. Processing: It is the process of converting the raw data into useful information. This

process is performed by the CPU of the computer. It takes the raw data from storage,

processes it and then sends back the processed data to storage.

4. Outputting: It is the process of presenting the processed data through output devices

like monitor, printer and speakers.

5. Controlling: This operation is performed by the control unit that is part of CPU. The

control unit ensures that all basic operations are executed in a right manner and

sequence.


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5.1.1 Input Devices (Input Unit)

Input device enables the user to send data, information, or control signals to a computer.

The Central Processing Unit (CPU) of a computer receives the input and processes it to

produce the output.

Example of Input unit devices: keyboard, mouse, scanner, joystick, Magnetic tape etc.

Input

Devices Characteristics Image

Keyboard

The keyboard is a basic input device that is used to enter data

into a computer or any other electronic device by pressing

keys. It has different sets of keys for letters, numbers,

characters, and functions. Keyboards are connected to a

computer through USB or a Bluetooth device for wireless

communication.

Mouse

The mouse is a hand-held input device which is used to move

cursor or pointer across the screen. It is designed to be used

on a flat surface and generally has left and right button and a

scroll wheel between them. Laptop computers come with a

touchpad that works as a mouse. It lets you control the

movement of cursor or pointer by moving your finger over the

touchpad. Some mouse comes with integrated features such as

extra buttons to perform different buttons.

Trackballs A trackball is also a pointing device which will work like a

mouse. It is mainly used for gaming and entertainment

purpose.

Digital

Pens

A digital pen is another input device which is mostly used

with tablets, PDAs, etc. A digital pen is also called as a Stylus

which helps to write or draw data over pad.

Scanners

The scanner uses the pictures and pages of text as input. It

scans the picture or a document. The scanned picture or

document then converted into a digital format or file and is

displayed on the screen as an output. It uses optical character

recognition techniques to convert images into digital ones.

Barcode

Readers

Barcode reader helps to read information which is printed as

bars in back of goods or items.

Voice

Recognition

System

Voice recognition system interprets or receives dictation or

spoken commands to authorize user.

Touch

screen

A touch screen is an input device which uses sensors to sense

touch of users to get input data.


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5.1.2 Output Devices

The output device displays the result of the processing of raw data that is entered in

the computer through an input device. There are a number of output devices that display

output in different ways such as text, images, hard copies, and audio or video.

Some of the popular output devices are:

1- Monitor

The monitor is the display unit or screen of the computer. It is the main output device that

displays the processed data or information as text, images, audio or video.

The types of monitors are given below

CRT Monitor

CRT monitors are based on the cathode ray tubes.

LCD Monitor

The LCD monitor is a flat panel screen that is compact and light-weight as compared to

CRT monitors. It is based on liquid crystal display technology which is used in the screens

of laptops, tablets, smart phones, etc.


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LED monitor

The LED monitor is an improved version of an LCD monitor. It also has a flat panel

display and uses liquid crystal display technology like the LCD monitors.

Plasma Monitor

The plasma monitor is also a flat panel display that is based on plasma display technology.

Plasma displays are brighter than liquid crystal displays (LCD) and also offer a wide

viewing angle than an LCD.


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2- Printer

A printer produces hard copies of the processed data. It enables the user, to print images,

text or any other information onto the paper. Based on the printing mechanism, the printers

are of two types: Impact Printers and Non-impact Printers.

o Impact Printers: They are of two types:

A. Character Printers

B. Line printers

o Non-impact printers: They are of two types:

A. Laser printers

B. Inkjet printers


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3- Projector

A projector is an output device that enables the user to project the output onto a

large surface such as a big screen or wall. It can be connected to a computer and similar

devices to project their output onto a screen. It uses light and lenses to produce magnified

texts, images, and videos. So, it is an ideal output device to give presentations or to teach a

large number of people.

Modern projects (digital projectors) come with multiple input sources such as HDMI ports

for newer equipment and VGA ports that support older devices. Some projectors are

designed to support Wi-Fi and Bluetooth as well. They can be fixed onto the ceiling,

placed on a stand, and more and are frequently used for classroom teaching, giving

presentations, home cinemas, etc.

4- Sound Systems

Sound systems are output devices which are used to get multimedia content such as

voice, music, etc., as output. Some of examples of sound systems are speakers,

headphones, and microphones.


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5.1.3 Processing Devices – Central Process Unit.

The Central Processing Unit (CPU) is called "the brain of computer" as it controls

operation of all parts of computer. CPU is installed or inserted into a CPU socket located

on the motherboard. Furthermore, it is provided with a heat sink to absorb and dissipate

heat to keep the CPU cool and functioning smoothly.

Generally, a CPU has three components:

o Control Unit

o ALU (Arithmetic and Logic Unit)

o Memory or Storage Unit

Central Processing Unit components


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1. Control unit: A control unit works by receiving input information that it converts into

control signals, which are then sent to the central processor. The computer's processor

then tells the attached hardware what operations to carry out. The functions that a

control unit performs are dependent on the type of CPU, due to the variance of

architecture between different manufacturers.

The following diagram illustrates how instructions from a program are processed.

Functions of Control Unit

Control unit performs following functions −

• It controls all activities of computer

• Supervises flow of data within CPU

• Directs flow of data within CPU

• Transfers data to Arithmetic and Logic Unit

• Transfers results to memory

• Fetches results from memory to output devices

2. ALU (Arithmetic and Logic Unit): It is the arithmetic logic unit, which performs

arithmetic and logical functions. Arithmetic functions include addition, subtraction,

multiplication division, and comparisons. Logical functions mainly include selecting,

comparing, and merging the data. A CPU may contain more than one ALU.

Furthermore, ALUs can be used for maintaining timers that help run the computer.

3. Memory or Storage Unit/ Registers: It is called Random access memory (RAM). It

temporarily stores data, programs, and intermediate and final results of processing. So,

it acts as a temporary storage area that holds the data temporarily, which is used to run

the computer.


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Types of CPU

CPUs are mostly manufactured by Intel and AMD, each of which manufactures its

own types of CPUs. In modern times, there are lots of CPU types in the market. Some of

the basic types of CPUs are described below:

Single Core CPU: Single Core is the oldest type of computer CPU, which was used in the

1970s. It has only one core to process different operations. It can start only one operation at

a time; the CPU switches back and forth between different sets of data streams when more

than one program runs. So, it is not suitable for multitasking as the performance will be

reduced if more than one application runs. The performance of these CPUs is mainly

dependent on the clock speed. It is still used in various devices, such as smartphones.

Dual Core CPU: As the name suggests, Dual Core CPU contains two cores in a single

Integrated Circuit (IC). Although each core has its own controller and cache, they are

linked together to work as a single unit and thus can perform faster than the single-core

processors and can handle multitasking more efficiently than Single Core processors.

Quad Core CPU: This type of CPU comes with two dual-core processors in one

integrated circuit (IC) or chip. So, a quad-core processor is a chip that contains four

independent units called cores. These cores read and execute instructions of CPU. The

cores can run multiple instructions simultaneously, thereby increases the overall speed for

programs that are compatible with parallel processing.

Quad Core CPU uses a technology that allows four independent processing units (cores) to

run in parallel on a single chip. Thus by integrating multiple cores in a single CPU, higher

performance can be generated without boosting the clock speed. However, the

performance increases only when the computer's software supports multiprocessing. The

software which supports multiprocessing divides the processing load between multiple

processors instead of using one processor at a time.

What is CPU Clock Speed?

The clock speed of a CPU or a processor refers to the number of instructions it can

process in a second. It is measured in gigahertz. For example, a CPU with a clock speed of

4.0 GHz means it can process 4 billion instructions in a second.


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5.1.4 Computer Memory

The computer memory holds the data and instructions needed to process raw data and

produce output. The computer memory is divided into large number of small parts known

as cells. Each cell has a unique address which varies from 0 to memory size minus one.

But, if we categorize memory on behalf of space or location, it is of four types:

A. Register memory

B. Cache memory

C. Primary memory

D. Secondary memory

Memory Units

Memory units are used to measure and represent data. Some of the commonly used

memory units are:

1. Bit: The computer memory units start from bit. A bit is the smallest memory unit to

measure data stored in main memory and storage devices. A bit can have only one

binary value out of 0 and 1.

2. Byte: It is the fundamental unit to measure data. It contains 8 bits or is equal to 8

bits. Thus a byte can represent 2*8 or 256 values.

3. Kilobyte: A kilobyte contains 1024 bytes.

4. Megabyte: A megabyte contains 1024 kilobytes.

5. Gigabyte: A gigabyte contains 1024 megabyte.

6. Terabyte: A terabyte contains 1024 gigabytes.

A. Register Memory

Register memory is the smallest and fastest memory in a computer. It is not a part

of the main memory and is located in the CPU in the form of registers, which are the

smallest data holding elements. A register temporarily holds frequently used data,

instructions, and memory address that are to be used by CPU. They hold instructions that

are currently processed by the CPU. All data is required to pass through registers before it

can be processed. So, they are used by CPU to process the data entered by the users.

Registers hold a small amount of data around 32 bits to 64 bits. The speed of a CPU

depends on the number and size (no. of bits) of registers that are built into the CPU.

Registers can be of different types based on their uses. Some of the widely used Registers

include Accumulator or AC, Data Register or DR, the Address Register or AR, Program

Counter (PC), I/O Address Register, and more.


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B. Cache Memory

Cache memory is a high-speed memory, which is small in size but faster than the

main memory (RAM). The CPU can access it more quickly than the primary memory. So,

it is used to synchronize with high-speed CPU and to improve its performance.

Cache memory can only be accessed by CPU. It can be a reserved part of the main

memory or a storage device outside the CPU. It holds the data and programs which are

frequently used by the CPU. So, it makes sure that the data is instantly available for CPU

whenever the CPU needs this data. In other words, if the CPU finds the required data or

instructions in the cache memory, it doesn't need to access the primary memory (RAM).

Thus, by acting as a buffer between RAM and CPU, it speeds up the system performance.

C. Primary Memory

Memory unit is a component of a computer system. It is used to store data,

instructions and information. It is also known as a main/primary/internal memory.

Computer memory is of two basic types – Primary memory(RAM and ROM) and

Secondary memory (hard drive, CD, etc). Random Access Memory (RAM) is primary-

volatile memory and Read Only Memory (ROM) is primary-non-volatile memory.


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There are two types of Primary memory: –

1. Random Access Memory

RAM, which stands for Random Access Memory, is a hardware device generally located

on the motherboard of a computer and acts as an internal memory of the CPU. It allows

CPU store data, program, and program results when you switch on the computer. It is the

read and write memory of a computer, which means the information can be written to it as

well as read from it.

RAM is a volatile memory, which means it does not store data or instructions

permanently. When you switch on the computer the data and instructions from the hard

disk are stored in the RAM, e.g., when the computer is rebooted, and when you open a

program, the operating system (OS), and the program are loaded into RAM, generally from

an HDD or SSD. CPU utilizes this data to perform the required tasks. As soon as you shut

down the computer, the RAM loses the data. So, the data remains in the RAM as long as

the computer is on and lost when the computer is turned off. The benefit of loading data

into RAM is that reading data from the RAM is much faster than reading from the hard

drive.

In simple words, we can say that RAM is like a person's short term memory, and

hard drive storage is like a person's long term memory. Short term memory remembers the

things for a short duration, whereas long term memory remembers for a long duration.

Short term memory can be refreshed with information stored in the brains long term

memory. A computer also works like this; when the RAM fills up, the processor goes to

the hard disk to overlay the old data in Ram with new data. It is like a reusable scratch

paper on which you can write notes, numbers, etc., with a pencil. If you run out of space on

the paper, you may erase what you no longer need; RAM also behaves like this, the

unnecessary data on the RAM is deleted when it fills up, and it is replaced with new data

from the hard disk which is required for the current operations.


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RAM comes in the form of a chip that is individually mounted on the motherboard

or in the form of several chips on a small board connected to the motherboard. It is the

main memory of a computer. It is faster to write to and read from as compared to other

memories such as a hard disk drive (HDD), solid-state drive (SSD), optical drive, etc.

A computer's performance mainly depends on the size or storage capacity of the RAM. If it

does not have sufficient RAM (random access memory) to run the OS and software

programs, it will result in slower performance. So, the more RAM a computer has, the

faster it will work. Information stored in RAM is accessed randomly, not in a sequence as

on a CD or hard drive. So, its access time is much faster.

Functions of RAM are as follows:

It stores data till it gets processed.

It stores instructions for data processing.

It acts as a working space where data processing takes place and intermediate

results are stored.

It stores processed data/results before it is sent to output devices.

Types of RAM:

Integrated RAM chips can be of two types:

1. Static RAM (SRAM)

Data is stored in transistors and requires a constant power flow. Because of the

continuous power, SRAM doesn‟t need to be refreshed to remember the data being

stored. SRAM is called static as no change or action i.e. refreshing is not needed to

keep the data intact. It is used in cache memories.

Advantage: Low power consumption and faster access speeds.

Disadvantage: Less memory capacities and high costs of manufacturing.

2. Dynamic RAM (DRAM)

Data is stored in capacitors. Capacitors that store data in DRAM gradually discharge

energy, no energy means the data has been lost. So, a periodic refresh of power is

required in order to function. DRAM is called dynamic as constant change or action

i.e. refreshing is needed to keep the data intact. It is used to implement main

memory.

Advantage: Low costs of manufacturing and greater memory capacities.

Disadvantage: Slow access speed and high power consumption.


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2. Read Only Memory ROM

ROM, which stands for read only memory, is a memory device or storage medium

that stores information permanently. It is also the primary memory unit of a computer

along with the random access memory (RAM). It is called read only memory as we can

only read the programs and data stored on it but cannot write on it. It is restricted to

reading words that are permanently stored within the unit.

The manufacturer of ROM fills the programs into the ROM at the time of

manufacturing the ROM. After this, the content of the ROM can't be altered, which means

you can't reprogram, rewrite, or erase its content later. However, there are some types of

ROM where you can modify the data.

ROM contains special internal electronic fuses that can be programmed for a

specific interconnection pattern (information). The binary information stored in the chip is

specified by the designer and then embedded in the unit at the time of manufacturing to

form the required interconnection pattern (information). Once the pattern (information) is

established, it stays within the unit even when the power is turned off. So, it is a non-

volatile memory as it holds the information even when the power is turned off, or you shut

down your computer.

The information is added to a RAM in the form of bits by a process known as

programming the ROM as bits are stored in the hardware configuration of the device. So,

ROM is a Programmable Logic Device (PLD). A simple example of ROM is the cartridge

used in video game consoles that allows the system to run many games. The data which is

stored permanently on personal computers and other electronic devices like smartphones,

tablets, TV, AC, etc. is also an example of ROM.

For example, when you start your computer, the screen does not appear instantly. It takes

time to appear as there are startup instructions stored in ROM which are required to start

the computer during the booting process. The work of the booting process is to start the

computer. It loads the operating system into the main memory (RAM) installed on your

computer. The BIOS program, which is also present in the computer memory (ROM) is

used by the microprocessor of the computer to start the computer during the booting

process. It allows you to open the computer and connects the computer with the operating

system.


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ROM is also used to store Firmware, which is a software program which remains attached

to the hardware or programmed on a hardware device like a keyboard, hard drive, video

cards, etc. It is stored in the flash ROM of a hardware device. It provides instructions to the

device to communicate and interact with other devices.

Types of Rom

1. Programmable Read Only Memory (PROM)

PROM is a blank version of ROM. It is manufactured as blank memory and programmed

after manufacturing. We can say that it is kept blank at the time of manufacturing. You can

purchase and then program it once using a special tool called a programmer.

Uses: It is used in cell phones, video game consoles, medical devices, RFID tags, and

more.

2. Erasable and Programmable Read Only Memory (EPROM)

EPROM is a type of ROM that can be reprogramed and erased many times.

Uses: EPROM is used widely in personal computers. Since EPROM chips do not require

power to retain their data, they are commonly used to store BIOS information and basic

software for modems, video cards, and other peripherals.

3. Electrically Erasable and Programmable Read Only Memory (EEPROM)

ROM is a type of read only memory that can be erased and reprogrammed repeatedly, up

to 10000 times. It is also known as Flash EEPROM as it is similar to flash memory.

Uses: The BIOS of a computer is stored in this memory.

Sr.No RAM ROM

1 It is volatile memory. It is non-volatile memory.

2 The contents are temporary; data is

lost when electricity supply is lost.

The contents are permanent; data is not lost

even when power is switched off.

3 Available in small storage capacity. Available in high storage capacity.

4 Processing speed is high. Processing speed is low.

5 User-defined programs can be

stored.

Generally, operating system supporting

programs can be stored.

6 Cost is very high. Cost effective.

7 It is of two types, SRAM and

DRAM.

It comes in different types such as PROM,

EPROM.


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D. Secondary Memory

The secondary storage devices which are built into the computer or connected to the

computer are known as a secondary memory of the computer. It is also known as external

memory or auxiliary storage.

The secondary memory is accessed indirectly via input/output operations. It is non-volatile,

so permanently stores the data even when the computer is turned off or until this data is

overwritten or deleted. The CPU can't directly access the secondary memory. First, the

secondary memory data is transferred to primary memory then the CPU can access it.

Some of the secondary memory or storage devices are described below:

1- Hard Disk:

It is a rigid magnetic disc that is used to store data. It permanently stores data and is

located within a drive unit.

The hard disk is also known as a hard drive. It is a rigid magnetic disc that stores data

permanently, as it is a non-volatile storage device. The hard disk is located within a drive

unit on the computer's motherboard and comprises one or more platters packed in an air-

sealed casing. The data is written on the platters by moving a magnetic head over the

platters as they spin. The data stored on a computer's hard drive generally includes the

operating system, installed software, and the user's files and programs, including pictures,

music, videos, text documents, etc.


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2- Solid-state Drive:

SSD (Solid State Drive) is also a non-volatile storage medium that is used to hold

and access data. Unlike a hard drive, it does not have moving components, so it offers

many advantages over SSD, such as faster access time, noiseless operation, less power

consumption, and more. As the cost of SSD has come down, it has become an ideal

replacement for a standard hard drive in desktop and laptop computers. It is also suitable

for notebooks, and tablets that don't require lots of storage.

3- USB flash drive (pen drive):

USB flash drive is a compact secondary storage device. It connects to a computer

via a USB port. It is commonly used to store and transfer data between computers. For

example, you can write a report using a computer and then copy or transfer it in the USB

flash drive. Later, you can connect this USB flash drive to a computer to see or edit your

report. You can also store your important documents and pictures, music, videos in the

USB flash drive and keep it at a safe place.

USB flash drive does not have movable parts; it comprises an integrated circuit

memory chip that stores the data. This chip is housed inside a plastic or aluminum casing.

The data storage capacity of the USB flash drive generally ranges from 2 GB to 1 TB.

Furthermore, it is a plug and play device as you don't need additional drives, software, or

hardware to use it.


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4- SD Card:

SD Card stands for Secure Digital Card. It is most often used in portable and mobile

devices such as smartphones and digital cameras. You can remove it from your device and

see the things stored in it using a computer with a card reader.

There are many memory chips inside the SD card that store the data; it does not have

moving parts. SD cards are not created equal, so they may differ from each other in terms

of speed, physical sizes, and capacity. For example, standard SD cards, mini SD cards, and

micro SD cards.

5- Compact Disk (CD):

Compact Disk is a portable secondary storage device in the shape of a round medium

disk. It is made of polycarbonate plastic. The concept of CD was co-developed by Philips

and Sony in 1982. The first CD was created on 17 August 1982 at the workshop of Philips

in Germany.

In the beginning, it was used for storing and playing sound recordings, later it was used for

various purposes such as for storing documents, audio files, videos, and other data like

software programs in a CD.


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How Does a CD Work?

The data or information is stored or recorded or encoded in CD digitally using a laser

beam that etches tiny indentations or bumps on its surface. The bump is called a pit, which

represents the number 0. Space, where the bump is not created, is called land, and it

represents the number 1. Thus, the data is encoded into a compact disc by creating pits (0)

and lands (1). The CD players use laser technology to read the optically recorded data.

6- DVD:

DVD is short for digital versatile disc or digital video disc. It is a type of optical media

used for storing optical data. Although it has the same size as a CD, its storage capacity is

much more than a CD. So, it is widely used for storing and viewing movies and to

distribute software programs as they are too large to fit on a CD. DVD was co-developed

by Sony, Panasonic, Philips, and Toshiba in 1995.

Types of DVDs:

DVDs can be divided into three main categories which are as follows:

o DVD-ROM (Read-Only): These types of DVDs come with media already

recorded on them, such as movie dvds. As the name suggests, data on these discs

cannot be erased or added, so these discs are known as a read-only or non-writable

DVD.

o DVD-R (Writable): It allows you to record or write information to the DVD.

However, you can write information only once as it becomes a read-only DVD

once it is full.

o DVD-RW (Rewritable or Erasable): This type of discs can be erased, written, or

recorded multiple times.

Briefly, There are primarily three types of optical storage devices, CD (compact disk),

DVD (digital video disk) and BD (blue ray disk). CDs can hold about 700 MB data DVD

can hold about 4.7 GB data and Blue ray disk can have 5 times the storage of DVD. Solid

state storage devices are becoming more and more popular and they are replacing disk

drives (both magnetic and optic). They require less energy and quieter.


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5.1.5 Other Components of Computer Hardware

1. Motherboard

The motherboard serves as a single platform to connect all of the parts of a

computer together. It connects the CPU, memory, hard drives, optical drives, video card,

sound card, and other ports and expansion cards directly or via cables. It can be

considered as the backbone of a computer.

The motherboard is mounted inside the case and is securely attached via small

screws through pre-drilled holes. Motherboard contains ports to connect all of the internal

components. It provides a single socket for CPU, whereas for memory, normally one or

more slots are available. Motherboards provide ports to attach the floppy drive, hard

drive, and optical drives via ribbon cables. Motherboard carries fans and a special port

designed for power supply.

There is a peripheral card slot in front of the motherboard using which video cards,

sound cards, and other expansion cards can be connected to the motherboard.

On the left side, motherboards carry a number of ports to connect the monitor, printer,

mouse, keyboard, speaker, and network cables. Motherboards also provide USB ports,

which allow compatible devices to be connected in plug-in/plug-out fashion. For example,

pen drive, digital cameras, etc.


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2. Graphics Card

A graphics card is a type of display adapter or video card installed within most

computing devices to display graphical data with high clarity, color, definition and overall

appearance. A graphics card provides high-quality visual display by processing and

executing graphical data using advanced graphical techniques, features and functions.

A graphics card is also known as a graphics adapter, graphics controller, graphics

accelerator card or graphics board.

Explains Graphics Card

A graphics card is primarily designed to remove the graphical processing tasks

from the processor or RAM. It includes a dedicated graphical processing unit (GPU) and a

dedicated RAM that help it to process graphical data quickly. Like most processors, a

graphics card also has a dedicated heat sink to keep the heat out of the GPU. A graphics

card enables the display of 3-D images, image rasterization, higher pixel ration, a broader

range of colors and more. Moreover, a graphics card includes various expansion ports such

as AGP, HDMI, TV and multiple monitor connectivity. A graphics card can be integrated

within the motherboard or be added on as an extension card.


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5.2 Computer - Software

Software is a set of programs, which is designed to perform a well-defined

function. A program is a sequence of instructions written to solve a particular problem.

There are two types of software: -

System Software

Application Software

5.2.1 System Software

The system software is a collection of programs designed to operate, control, and

extend the processing capabilities of the computer itself. System software is generally

prepared by the computer manufacturers. These software products comprise of programs

written in low-level languages, which interact with the hardware at a very basic level.

System software serves as the interface between the hardware and the end users.

Some examples of system software are Operating System, Compilers, Interpreter,

Assemblers, etc.

Operating System

An Operating System (OS) is the most important software that runs on a computer.

OS acts as an interface between the user and the computer hardware and controls the

execution of all kinds of programs which is performs all the basic tasks like file

management, memory management, process management, handling input and output, and

controlling peripheral devices such as disk drives and printers. It also allows you to

communicate with the computer without knowing how to speak the computer's language.

Without an operating system, a computer is useless.

The Operating System is a program with the following features −

An operating system is a program that acts as an interface between the software

and the computer hardware.

It is an integrated set of specialized programs used to manage overall resources and

operations of the computer.

It is a specialized software that controls and monitors the execution of all other

programs that reside in the computer, including application programs and other

system software.


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5.2.2 Application Software

Application software products are designed to satisfy a particular need of a

particular environment. All software applications prepared in the computer lab can come

under the category of Application software.

Application software may consist of a single program, such as Microsoft's notepad

for writing and editing a simple text. It may also consist of a collection of programs, often

called a software package, which work together to accomplish a task, such as a

spreadsheet package.

Figure 1: Application Software Location

Examples of Application software are the following: -

Payroll Software

Student Record Software

Inventory Management Software

Income Tax Software

Railways Reservation Software

Microsoft Office Suite Software

Microsoft Word

Microsoft Excel

Microsoft PowerPoint


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Features of application software are as follows: -

Close to the user

Easy to design

More interactive

Generally written in high-level language

Easy to understand

Easy to manipulate and use

Sr.No. Software Hardware

1 It is a collection of programs to

bring computer hardware system

into operation.

It includes physical components of

computer system.

2 It includes numbers, alphabets,

alphanumeric symbols, identifiers,

keywords, etc.

It consists of electronic components like

ICs, diodes, registers, crystals, boards,

insulators, etc.

3 Software products evolve by

adding new features to existing

programs to support hardware.

Hardware design is based on architectural

decisions to make it work over a range of

environmental conditions and time.

4 It will vary as per computer and

its built-in functions and

programming language.

It is mostly constructed for all types of

computer systems.

5 It is designed and developed by

experienced programmers in high-

level language.

The hardware can understand only low-

level language or machine language.

6 It is represented in any high-level

language such as BASIC,

COBOL, C, C++, JAVA, etc.

The hardware works only on binary

codes 1‟s and 0‟s.

7 The software is categorized as

operating system, utilities,

language processor, application

software, etc.

The hardware consists of input devices,

output devices, memory, etc.


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6. Computer Numbering Systems

The language we use to communicate with each other is comprised of words and

characters. We understand numbers, characters and words. But this type of data is not

suitable for computers. Computers only understand the numbers.

So, when we enter data, the data is converted into electronic pulse. Each pulse is identified

as code and the code is converted into numeric format by ASCII. It gives each number,

character and symbol a numeric value (number) that a computer understands. So to

understand the language of computers, one must be familiar with the number systems.

The Number Systems used in computers are:

Binary number system

Decimal number system

Octal number system

Hexadecimal (hex) number system

1. Binary Number System

Binary Number System is a number system in which we represent the numbers by

using only two symbols i.e. 0 or 1. The binary system is applied internally by almost all

latest computers and computer-based devices because of its direct implementation in

electronic circuits using logic gates. Every digit is referred to as a bit.

Example

Binary Number: 101012

Calculating Decimal Equivalent:

Step Binary Number Decimal Number

Step 1 101012 ((1 x 24) + (0 x 2

3) + (1 x 2

2) + (0 x 2

1) + (1 x 2

0))10

Step 2 101012 (16 + 0 + 4 + 0 + 1)10

Step 3 101012 2110

Note − 101012 is normally written as 10101.


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2. Decimal Number System

In decimal number system we have 10 digits – 0 to 9 to represent the numbers.

Hence, the base value of the Decimal Number system is 10. Decimal number system is

used when there are 10 possible outputs of a system. For example, top 10 students from a

class. The number system that we use in our day-to-day life is the decimal number system.

Decimal number system has base 10 as it uses 10 digits from 0 to 9. In decimal number

system, the successive positions to the left of the decimal point represent units, tens,

hundreds, thousands, and so on.

Each position represents a specific power of the base (10). For example, the

decimal number 1234 consists of the digit 4 in the unit's position, 3 in the tens position, 2

in the hundreds position, and 1 in the thousands position. Its value can be written as

(1 x 1000) + (2 x 100) + (3 x 10) + (4 x l)

(1 x 103) + (2 x 102) + (3 x 101) + (4 x l00)

1000 + 200 + 30 + 4

Decimal to Binary and Binary to Decimal Number System Let us convert decimal number (87)10 to binary number.

Reminder Decimal

Number Base of Binary

1 87 2

1 43 2

1 21 2

0 10 2

1 5 2

0 2 2

1 1 2

So, in the above example. We first identified 2 is the base of the binary (target number

system). Then, we divided the given decimal number (87) with the base 2. And then we

noted the remainder in every step. And finally, we reversed the remainder and got the

answer –

(1010111)2.

Let us convert binary number (1011001)2 to decimal number.


47

3. Octal Number System

Characteristics of the octal number system are as follows −

Uses eight digits, 0,1,2,3,4,5,6,7

Also called as base 8 number system

Example

Octal Number: 125708

Calculating Decimal Equivalent:

Step Octal Number Decimal Number

Step 1 125708 ((1 x 84) + (2 x 8

3) + (5 x 8

2) + (7 x 8

1) + (0 x 8

0))10

Step 2 125708 (4096 + 1024 + 320 + 56 + 0)10

Step 3 125708 549610

Note − 125708 is normally written as 12570.

4. Hexadecimal Number System

Characteristics of hexadecimal number system are as follows −

Uses 10 digits and 6 letters, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F

Letters represent the numbers starting from 10. A = 10. B = 11, C = 12, D = 13, E =

14, F = 15

Also called as base 16 number system

Each position in a hexadecimal number represents a 0 power of the base (16).

Example, 160

Last position in a hexadecimal number represents a x power of the base (16).

Example 16x where x represents the last position – 1


48

Example

Hexadecimal Number: 19FDE16

Calculating Decimal Equivalent: -

Step Binary

Number Decimal Number

Step 1 19FDE16 ((1 x 164) + (9 x 16

3) + (F x 16

2) + (D x 16

1) + (E x 16

0))10

Step 2 19FDE16 ((1 x 164) + (9 x 16

3) + (15 x 16

2) + (13 x 16

1) + (14 x 16

0))10

Step 3 19FDE16 (65536+ 36864 + 3840 + 208 + 14)10

Step 4 19FDE16 10646210

Note − 19FDE16 is normally written as 19FDE.


49

7. Programming Languages

A program is a set of instructions that help computer to perform tasks. This set of

instructions is also called as scripts. Programs are executed by processor whereas scripts

are interpreted. The languages that are used to write a program or set of instructions are

called "Programming languages". Programming languages are broadly categorized into

three types −

Machine level language

Assembly level language

High-level language

1. Machine Level Language

Machine language is lowest level of programming language. It handles binary data

i.e., 0’s and 1’s. It directly interacts with system. Machine language is difficult for human

beings to understand as it comprises combination of 0‟s and 1‟s. There is software which

translate programs into machine level language. Examples include operating systems like

Linux, UNIX, Windows, etc. In this language, there is no need of compilers and

interpreters for conversion and hence the time consumption is less. However, it is non-

readable to humans.

2. Assembly Level Language

Assembly language is a middle-level language. It consists of a set of instructions in

a specific format called commands. It uses symbols to represent field of instructions. It is

very close to machine level language. The computer should have assembler to translate

assembly level program to machine level program. Examples include ADA, PASCAL,

etc. It is in human-readable format and takes lesser time to write a program and debug it.

However, it is a machine dependent language.

Assembly Language Machine Code

SUB AX, BX 0010101110000011

MOV CX, AX 100010111001000

MOV DX, 0 10111010000000000000000


50

3. High-level Language

High-level language uses format or language that is most familiar to users. The

instructions in this language are called codes or scripts. The computer needs a compiler

and interpreter to convert high-level language program to machine level language.

Examples include C++, Python, Java, etc. It is easy to write a program using high level

language and is less time-consuming. Debugging is also easy and is a human-readable

language. Main disadvantages of this are that it takes lot of time for execution and

occupies more space when compared to Assembly- or Machine-level languages.

Following is a simple example for a high-level language.

if age < 18 {

printf("You are not eligible to vote");

} else {

printf("You are eligible to vote");

}


51

8. Information Technology

Information technology (IT) is the use of any computers, storage, networking and

other physical devices, infrastructure and processes to create, process, store, secure and

exchange all forms of electronic data. Typically, IT is used in the context of enterprise

operations as opposed to personal or entertainment technologies. The commercial use of IT

encompasses both computer technology and telephony.

Information Technology (IT) is a business sector that deals with computing,

including hardware, software, telecommunications and generally anything involved in the

transmittal of information or the systems that facilitate communication. IT typically refers

to equipment such as computers, data storage devices, networks and also communication

devices. Information Technology means the use of hardware, software, services and

supporting infrastructure to manage and deliver information using voices, data and video.

Information Technology “IT” is one of the fastest growing industry in today‟s unstable

economy. Why? Because many businesses, Government organizations, Industries want to

automate their business and day-to-day processes.

1.2.1 Information Technology Examples

1. Software and support for office automation systems such as word processing and

spreadsheets, as well as the computer to run them.

2. Data networks and all associated communications equipment such as servers, bridges,

routers, hubs and wiring.

3. Peripherals directly connected to computer information systems used to collect or

transmit audio, video or graphic information, such as scanners and digitizers.

4. Voice response systems that interact with a computer database or application.

5. Video conferencing equipment.

6. The state radio communications network.

7. Computers and network systems used by teachers, trainers and students for educational

purpose.

8. “Open” computer systems that monitor or automate mechanical or chemical processes

and also store information used by computer applications for analysis and decision

making.

https://byte-notes.com/information-technology-definition-and-examples/#simple-table-of-contents-1


52

Chapter Two

Computer Networks


53

1. Computer Network

Computer network is an interconnection between two or more hosts/computers.

The connectivity can be physical by using cables or virtual using wireless network.

Different types of networks include LAN, WAN, MAN, etc., as shown below:

Uses of Computer Network:

It allows you to share resources such as printers, scanners, etc.

You can share expensive software and database among network users.

It facilitates communications from one computer to another computer.

It allows the exchange of data and information among users through a network.

Popular Computer Networks:

Local Area Network (LAN)

Metropolitan Area Network (MAN)

Wide Area Network (WAN)


54

1.1 Local Area Network (LAN)

As the name suggests, the local area network is a computer network that operates in

a small area, i.e., it connects computers in a small geographical area like within an office,

company, school, or any other organization. So, it exists within a specific area, e.g. home

network, office network, school network, etc.

A local area network may be a wired or wireless network or a combination of both.

The devices in a LAN are generally connected using an Ethernet cable, which offers an

interface to connect multiple devices like router, switches, and computers. For example,

using a single router, few Ethernet cables, and computers, you can create a LAN at your

home, office, etc. In this network, one computer may act as a server and other computers,

which are part of the network, may serve as clients.

Figure 2: Local Area Network

Topologies of LAN:

Topology: It refers to the arrangement of computers (nodes) in a computer network. The

main topologies of a local area network are as follows:

1. Ring Topology:

As the name suggests, in a ring topology, the computers are connected in a circular and

closed loop. The message in this topology moves only in one direction around the ring

from one node to another node and is checked by each node for a matching destination

address.


55

2. Star Topology

In this topology, all the computers are separately connected to a central node or connection

point, which can be a server, a hub, a router, or a switch. This topology offers an advantage

that if a cable does not work, only the respective node will suffer, the rest of the nodes will

work smoothly. All data or messages that one node sends to another passes through the

central hub.

3. Bus Topology

In this arrangement, the nodes (computers) are connected through interface connectors to a

single communication line (central cable) that carries the message in both the directions.

Primary Functions of LAN:

o Sharing of files: It allows you to share or transfer files from one computer to

another computer within the LAN. For example, in a bank, it can be used to send a

file with the details of transactions of a customer from the server to clients.

o Sharing of printers: It also allows shared access to a printer, file servers, etc. For

example, ten computers that are connected through LAN can use a single printer,

file server, fax machine, etc.

o Sharing of Computational capabilities: It allows the clients to access to the

computational power of a server, e.g., an application server as some applications

which run on clients in a LAN may require higher computational capabilities.

o Mail and message related services: It allows sending and receiving mails between

computers of a LAN. You are required to have a mail server for this.

o Database services: It also allows storing and retrieving data with the help of a

database server.


56

Benefits of LAN:

o It offers a higher operating speed than WAN and MAN.

o It is less expensive and easy to install and maintain.

o It perfectly fulfills the requirement of a specific organization, such as an office,

school, etc.

o It can be wired or wireless or a combination of both.

o It is more secure than other networks as it is a small set up that can be easily taken

care of.

1.2 Metropolitan Area Network (MAN)

MAN is a high-speed network that spreads over a large geographical area such as

a metro city or town. It is set up by connecting the local area networks using routers

and local telephone exchange lines. It can be operated by a private company, or it may

be a service provided by a company such as a local telephone company.

MAN is ideal for the people of a relatively large area who want to share data or

information. It provides fast communication via high-speed carriers or transmission

media such as copper, fiber optics, and microwaves. The commonly used protocols for

MAN are X.25, Frame Relay, Asynchronous Transfer Mode (ATM), xDSL (Digital

Subscriber Line), ISDN (Integrated Services Digital Network), ADSL (Asymmetrical

Digital Subscriber Line), and more.

The area covered by MAN is larger than the LAN but smaller than a WAN. Its network

ranges from 5 to 50 km. Furthermore, it also provides uplinks for connecting LANs to

WANs and the internet. An organization can use a MAN to connect all of its LANs

located at its different offices across the city.

Figure 3: Wide Area Network


57

Advantages of MAN:

o Less Expensive: It is less expensive to set up a MAN and to connect it to a WAN.

o High Speed: The speed of data transfer is more than WAN.

o Local Emails: It can send local emails fast.

o Access to the Internet: It allows you to share your internet connection, and thus

multiple users can have access to high-speed internet.

o Easy to set up: You can easily set up a MAN by connecting multiple LANs.

o High Security: It is more secure than WAN.

1.3 Wide Area Network (WAN):

WAN extends over a large geographical area. It is not confined within an office,

school, city, or town and is mainly set up by telephone lines, fiber optic, or satellite

links. It is mostly used by big organizations like banks and multinational companies to

communicate with their branches and customers across the world. Although it is

structurally similar to MAN, it is different from MAN in terms of its range, e.g., MAN

covers up to 50 Kms, whereas WAM covers distances larger than 50 Km, e.g., 1000km

or more.

A WAN works by using TCP/IP protocol in combination with networking devices such

as switches, routers, firewalls, and modems. It does not connect individual computers;

rather, they are designed to link small networks like LANs and MANs to create a large

network. The internet is considered the largest WAN in the world as it connects various

LANs and MANs through ISPs.

The computers are connected to the wide area network through public networks, such

as telephone systems, leased lines or satellites. The users of a WAN do not own the

network as it is a large setup connecting the remote computer systems. However, they

are required to subscribe to a service provided by a telecommunication provider to use

this network.


58

2. Internet

Internet is a global communication system that links together thousands of

individual networks. It allows exchange of information between two or more computers on

a network. Thus, internet helps in transfer of messages through mail, chat, video and audio

conference, etc. It has become mandatory for day-to-day activities: bills payment, online

shopping and surfing, tutoring, working, communicating with peers, etc.

It uses standard internet protocol suite (TCP/IP) to connect billions of computer

users worldwide. Protocol used is TCP/IP. This protocol connects any two networks that

differ in hardware, software and design. TCP/IP provides end to end transmission, i.e.,

each and every node on one network has the ability to communicate with any other node

on the network. It is set up by using cables such as optical fibers and other wireless and

networking technologies. At present, internet is the fastest mean of sending or exchanging

information and data between computers across the world.

Why is the Internet Called a Network?

Internet is called a network as it creates a network by connecting computers and

servers across the world using routers, switches and telephone lines, and other

communication devices and channels. So, it can be considered a global network of physical

cables such as copper telephone wires, fiber optic cables, tv cables, etc. Furthermore, even

wireless connections like 3G, 4G, or Wi-Fi make use of these cables to access the Internet.

Internet is different from the World Wide Web as the World Wide Web is a

network of computers and servers created by connecting them through the internet. So, the

internet is the backbone of the web as it provides the technical infrastructure to establish

the WWW and acts as a medium to transmit information from one computer to another

computer. It uses web browsers to display the information on the client, which it fetches

from web servers.

https://www.javatpoint.com/what-is-world-wide-web

https://www.javatpoint.com/www-full-form


59

Advantages of the Internet:

Instant Messaging: You can send messages or communicate to anyone using

internet, such as email, voice chat, video conferencing, etc.

Get directions: Using GPS technology, you can get directions to almost every

place in a city, country, etc. You can find restaurants, malls, or any other service

near your location.

Online Shopping: It allows you to shop online such as you can be clothes, shoes,

book movie tickets, railway tickets, flight tickets, and more.

Pay Bills: You can pay your bills online, such as electricity bills, gas bills, college

fees, etc.

Online Banking: It allows you to use internet banking in which you can check

your balance, receive or transfer money, get a statement, request cheque-book, etc.

Online Selling: You can sell your products or services online. It helps you reach

more customers and thus increases your sales and profit.

Work from Home: In case you need to work from home, you can do it using a

system with internet access. Today, many companies allow their employees to

work from home.

Entertainment: You can listen to online music, watch videos or movies, play

online games.

Cloud computing: It enables you to connect your computers and internet-enabled

devices to cloud services such as cloud storage, cloud computing, etc.

Career building: You can search for jobs online on different job portals and send

you CV through email if required.


60

3. Web Browsing Software

"World Wide Web" or simple "Web" is the name given to all the resources of

internet. The special software or application program with which you can access web is

called "Web Browser".

Launching a Web Browser

Web browser is an application that is located on a computer‟s disk. Once you have an

internet connection, you can launch a web browser using the following methods −

Method 1

Step 1 − Go to "Start Menu".

Step 2 − From the menu opened, click on the web browser (Mozilla, Google Chrome,

Internet Explorer).

Method 2 − Alternate way is to click the shortcut icon on the taskbar or desktop.


61

Popular Web Browsing Software

The most popular web browsing software includes:

1. Google Chrome

Google Chrome is a web browsing software developed in the year 2008 by Google

Inc. First, it was designed for windows platform, and later adopted to Linux, Macintosh,

and even Android. It is written using C++, Assembly, Python, and JavaScript.

2. Mozilla Firefox

Mozilla Firefox is a web browsing software developed in the year 2002 by the

Mozilla Foundation. It is designed to work on all operating systems like Windows,

Macintosh, Linux, and Android. It is written using C++, JavaScript, Rust, C, CSS, XUL,

and XBL.

3. Opera

Opera is a web browsing software developed in the year 1995 by Opera Software.

It is designed to work on all operating systems like Windows, Macintosh, and Linux and

is written using C++ language.

4. Internet Explorer

Internet Explorer is a web browsing software developed in the year 1995 by

Microsoft. It is designed to work on all operating systems like Windows, Macintosh,

Linux and Android and is written using C++ language.

Search Engines

Search Engine is an application that allows you to search for content on the web. It

displays multiple web pages based on the content or a word you have typed.

The most popular search engines are listed below.

1. Google

Google is the most popular and robust search engine launched in the year 1997 by

Google Inc. It was developed by Larry Page and Sergey Brin. It is written using C, C++

and Python. Beyond searching content, it also provides weather forecasts, sports score,

temperatures, area codes, language translation, synonyms, etc. Now-a-days the

advancement is still more, that it displays maps in a touch.


62

2. Bing

Bing is also a popular search engine launched by Microsoft in the year 2009. It is

written using ASP .Net language. It is used to search web content, video, images, maps,

etc.

3. Yahoo

Yahoo is a common search engine launched by Yahoo in the year 1995. It is a

multilingual search engine and written using PHP language.

4. Ask

Ask is the most popular search engine and application for e-business which was launched

by IAO in the year 1996. It was developed by Garrett Gruener, David Warthen, and

Douglas Leeds.


63

Search for The Content

Search Engine helps to search for content on web using the following steps.

Step 1 − Launch your web browser.

Step 2 − In "Address bar/Location", type the search engine you want to use and press

enter.

Step 3 − Type the content you want to search in the "search text box" and press enter.

Step 4 − It displays a list of web pages from which you can select corresponding

content/web page you want.


64

4. E- Mail

Electronic mail (email or e-mail) is a method of exchanging messages ("mail")

between people using electronic devices. More plainly, e-mail is a message that may

contain text, files, images, or other attachments sent through a network to a specified

individual or group of individuals.

Email operates across computer networks, primarily the Internet. Today's email

systems are based on a store-and-forward model. Email servers accept, forward, deliver,

and store messages. Neither the users nor their computers are required to be online

simultaneously.

Email messages include three components, which are as follows:

o Message envelope: It depicts the email's electronic format.

o Message header: It contains email subject line and sender/recipient information.

o Message body: It comprises images, text, and other file attachments.

Advantages of Email

There are many advantages of email, which are as follows:

o Cost-effective: Email is a very cost-effective service to communicate with others

as there are several email services available to individuals and organizations for

free of cost. Once a user is online, it does not include any additional charge for the

services.

o Email offers users the benefit of accessing email from anywhere at any time if they

have an Internet connection.

o Email offers you an incurable communication process, which enables you to send a

response at a convenient time. Also, it offers users a better option to communicate

easily regardless of different schedules users.

o Speed and simplicity: Email can be composed very easily with the correct

information and contacts. Also, minimum lag time, it can be exchanged quickly.


65

o Mass sending: You can send a message easily to large numbers of people through

email.

o Email exchanges can be saved for future retrieval, which allows users to keep

important conversations or confirmations in their records and can be searched and

retrieved when they needed quickly.

o Email provides a simple user interface and enables users to categorize and filter

their messages. This can help you recognize unwanted emails like junk and spam

mail. Also, users can find specific messages easily when they are needed.

o As compared to traditional posts, emails are delivered extremely fast.

o Email is beneficial for the planet, as it is paperless. It reduces the cost of paper and

helps to save the environment by reducing paper usage.

o It also offers a benefit to attaching the original message at the time you reply to an

email. This is beneficial when you get hundreds of emails a day, and the recipient

knows what you are talking about.

o Furthermore, emails are beneficial for advertising products. As email is a form of

communication, organizations or companies can interact with a lot of people and

inform them in a short time.

Gmail

Gmail is a free email service developed by Google. Users can access Gmail on the

web and using third-party programs that synchronize email content through POP or IMAP

protocols. Gmail started as a limited beta release on April 1, 2004 and ended its testing

phase on July 7, 2009.

At launch, Gmail had an initial storage capacity offer of one gigabyte per user, a

significantly higher amount than competitors offered at the time. Today, the service comes

with 15 gigabytes of storage. Users can receive emails up to 50 megabytes in size,

including attachments, while they can send emails up to 25 megabytes. In order to send

larger files, users can insert files from Google Drive into the message. Gmail has a search-

oriented interface and a "conversation view" similar to an Internet forum. By 2018, Gmail

had 1.5 billion active users worldwide.


66

Chapter Three

Computer Viruses and Crimes


67

1. Computer Viruses

A computer virus is defined as a piece code or program which is executed in a

target computer to hamper the smooth functioning of the PC. It replicates itself and can

quickly affect hosts of other computers, thus paralyzing the entire network. So, it is

important for you to know how to remove it as soon as possible because a malware

infection can severely damage your data. It showed its existence in the year 1986 when the

first computer virus was created by the name of Brain for MS-DOS operating systems.

Mainly a boot sector Virus, it spreads through floppy disks. Nowadays, there are several

types of malicious software, which are developed using advanced coding technology.

Types of PC Virus

Although there are thousands of infectious programs that can affect your PC, these

are categorized on the basis of their infection targets.

1. Boot Sector Virus

Boot Sector Virus infects the Master Boot Record (MBR) of hard disks. Some virus

also infects the boot sector of hard drives. It spreads via external sources, for example, an

infected floppy disk or USB drive.

2. Macro Virus

A macro virus usually targets Microsoft Word, Microsoft Outlook, and similar

applications. The piece of the virus is embedded in documents or emails. And you

accidentally open the file, the virus gets activated and can spread to other files and folders.

3. Email Virus

Email Virus uses email medium to spread and infect PCs. These types of malware

come hidden in email attachments and execute as soon as you download or open the

attachment.

https://en.wikipedia.org/wiki/Macro_virus


68

How do Computer Viruses Spread?

A computer virus may spread if any external virus infected hard drive is inserted

into your PC. These removable devices can be a pen drive, an external hard disk or a

floppy drive. Apart from external hard drives, it spreads via email attachments, which can

easily carry malware. Your computer can also get infected if you download software,

movies, songs, etc. from untrusted websites.

Symptoms of Computer Virus Infection

You can easily identify the symptoms of computer virus infection. One major

indication is that your PC getting extremely slow. Another symptom can be your existing

firewall protection getting disabled. You will also experience frequent crashes of

applications running on your PC. Other alerts can be hard drive malfunction, error

messages & pop-ups.

How to Prevent Viruses?

In order to prevent viruses from infecting your computer, you must follow certain best

practices such as:

Do not insert removable devices/USB devices without scanning using a virus

scanner

Abstain from downloading software from untrusted websites

Don‟t open email attachments without verifying the sender id, content, and purpose

Use a premium antivirus software rather than free software as those may not be

capable of providing 100% protection.

How to Remove a Virus?

In order to eliminate the possibility of infection on your device, you need to first

delete all temporary files to speed up the virus scan process. Once you have deleted the

temp files, scan your PC using an antivirus software. You can use REVE Antivirus, which

scans computer threats using the turbo scan technology. This results in quick virus

detection and removal. After the removal of malicious code or infectious files from your

computer, always keep your antivirus software updated, so that any kind of latest threat can

be detected.

https://www.reveantivirus.com/en/product/antivirus

https://www.reveantivirus.com/en/computer-security-threats/computer-virus#downloadModal3

https://www.reveantivirus.com/en/computer-security-threats/computer-virus#downloadModal3


69

Computer Crimes

Cybercrime, or computer-oriented crime, is a crime that involves a computer and a

network. The computer may have been used in the commission of a crime, or it may be the

target. Cybercrime may threaten a person, company or a nation's security and financial

health.

There are many privacy concerns surrounding cybercrime when confidential

information is intercepted or disclosed, lawfully or otherwise. Debarati Halder and K.

Jaishankar further define cybercrime from the perspective of gender and defined

'cybercrime against women' as "Crimes targeted against women with a motive to

intentionally harm the victim psychologically and physically, using modern

telecommunication networks such as internet and mobile phones". Internationally, both

governmental and non-state actors engage in cybercrimes, including espionage, financial

theft, and other cross-border crimes. Cybercrimes crossing international borders and

involving the actions of at least one nation-state is sometimes referred to as cyberwarfare.

Classifications of Computer crime

Computer crime encompasses a broad range of activities.

1. Financial fraud crimes

2. Cyberterrorism

3. Cyberextortion

4. Cybersex trafficking

5. Cyberwarfare

6. Computer as a target

7. Computer as a tool

8. Obscene or offensive content

9. Online harassment

10. Drug trafficking

Combating computer crime

1. Investigation

2. Prevention

3. Legislation

4. Awareness

5. Intelligence


70

Chapter Four

Getting Started

with Windows

CHAPTER 1

Getting Started with WindowsTo do something useful with your computer and with Windows 10, you need to learn a few basic tasks and techniques. These include exploring the screen, learning how to put your computer to sleep, how to restart and shut down your computer, how to connect to your network, and how to create a Microsoft account. You also need to learn how to work with apps, including installing them, starting them, and switching between them when you have multiple apps running. This chapter also shows you how to update and uninstall apps.

Explore the PC Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Explore the Tablet Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Put Windows to Sleep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Restart or Shut Down Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Connect to Your Wireless Network . . . . . . . . . . . . . . . . . . . . . . . . . .8

Switch to a Microsoft Account . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Install an App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Start an App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Switch Between Running Apps . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Update an App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Uninstall an App . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

4

Before getting to the specifics of working with Windows 10, take a few seconds to familiarize yourself with the basic elements of the screen. These elements include the Start screen’s app tiles, live tiles, your user tile, and the Desktop tile.Understanding where these elements appear on the Start screen and what they are used for will help you

work through the rest of this book and will help you navigate Windows and its applications on your own. This section covers the screen you see on a PC. If you are using a Touch PC or a tablet, see the next section, “Explore the Tablet Screen.”

Explore the PC Screen

A Desktop IconAn icon on the desktop represents a program or Windows feature. A program you install often adds its own icon on the desktop.

C DesktopThis is the Windows “work area,” meaning that it is where you work with your programs and documents.

H Notification AreaThis area displays small icons that notify you about things that are happening on your computer. For example, you see notifications if your printer runs out of paper or if an update to Windows is available over the Internet.

I Time and DateThis is the current time and date on your computer. To see the full date, position the mouse ( ) over the time. To change the date or time, click the time.

B Mouse PointerWhen you move your mouse, this pointer moves along with it.

D Start ButtonYou use this button to start programs and launch many of Windows’ features.

E Search BoxYou use this box to search for items on your PC or on the Internet.

F Taskbar IconsYou use these icons to launch some Windows features with just a mouse click.

G TaskbarThe programs you have open appear in the taskbar. You use this area to switch between programs if you have more than one running at a time.

5

chapter

1If you are using a touch‐based PC or a tablet device, Windows 10 will automatically reconfigure the screen into tablet mode, which is designed to make it easier for you to navigate and launch items using touches and other gestures. However, you

might find that using this new interface is not easier at first. To get more out of this interface and to learn how to operate your Touch PC or tablet, you need to familiarize yourself with Windows 10’s tablet mode.

A Tablet mode displays the Start screen, which consists of tiles for several common apps.

B In an app, you can click Back ( ) to return to either the previous app screen or to the Start screen.

C To return directly to the Start screen, you can click Start ( ).

1 To see more commands, click Menu ( ).

Windows displays a menu of commands.

2 To hide the commands, click Menu ( ) again.

D To toggle tablet mode on and off, you can click Action Center ( ) and then click Tablet Mode.

Explore the Tablet Screen

Explore the Tablet Screen

6

You can make your computer more energy efficient by putting Windows into sleep mode when you are not using the computer. Sleep mode means that your computer is in a temporary low‐power mode. This saves electricity when your computer is plugged in, and it saves battery power when your computer is unplugged.

In sleep mode, Windows keeps your apps open. This is handy because it means that when you return from sleep mode, after you sign in to Windows again, you can immediately get back to what you were doing.

1 Click Start ( ).

The Start menu appears.

2 Click Power ( ).

3 Click Sleep.

Windows activates sleep mode.

Note: To return from sleep mode, press your computer’s Power button.

Put Windows to Sleep

Put Windows to Sleep

2

3

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1Restart or Shut Down Windows

1 Shut down all your running programs.

Note: Be sure to save your work as you close your programs.

2 Click Start ( ).

The Start menu appears.

3 Click Power ( ).

4 Click a command:

A Click Restart to shut down and then start your computer.

B Click Shut Down to turn off your computer.

You can restart Windows, which means that it shuts down and starts up again immediately. This is useful if your computer is running slowly or acting funny. Sometimes a restart solves the problem.Alternatively, when you complete your work, you could shut down Windows. However, do not just shut off your computer’s power because doing so can

cause problems: If you have documents with unsaved changes, you may lose those changes; you also could damage one or more Windows system files, which could make your system unstable. Therefore, you should always follow the proper steps when shutting down your PC.

Restart or Shut Down Windows

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A Windows displays a list of wireless networks in your area.

2 Click your network.

3 To have Windows connect to your network automatically in the future, click Connect automatically ( changes to ).

4 Click Connect.

1 Click Network ( ).

Connect to Your Wireless Network

If you have a wireless access point and your computer has built‐in wireless networking capabilities, you can connect to the wireless access point to access your network. If your wireless access point is connected to the Internet, then connecting to the wireless network gives your computer Internet access, as well.

Most wireless networks are protected with a security key, which is a kind of password. You need to know the key before attempting to connect. However, after you have connected to the network once, Windows remembers the password and connects again automatically whenever the network comes within range.

Connect to Your Wireless Network


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1

Windows asks if it can locate the other computers and devices on your network.

7 Click Yes.

Windows connects to the network.

C The network icon changes from Disconnected ( ) to Connected ( ) to indicate that you now have a wireless network connection.

If the network is protected by a security key, Windows prompts you to enter it.

5 Type the security key.

B If you want to be certain that you typed the security key correctly, temporarily click and hold Display Password Characters ( ).

6 Click Next.

How do I disconnect from my wireless network?To disconnect from the network, follow these steps:1 Click Network ( ).

2 Click your network.

3 Click Disconnect. Windows disconnects from the wireless network.si

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The Accounts window appears.

4 Click Sign in with a Microsoft account instead .

Start a Microsoft Account

1 Click Start (not shown).

2 Click Settings (not shown).

Windows opens the Settings app.

3 Click Accounts.

Switch to a Microsoft Account

You can get much more out of Windows by using a Microsoft account. When you connect a Microsoft account to your Windows user account, many previously inaccessible Windows features become immediately available. For example, you can use the Mail app to access your email and the OneDrive app

to store documents online. You can also download apps from the Windows Store, access your photos and documents anywhere online, and even sync your settings with other PCs for which you use the same account.

Switch to a Microsoft Account


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1The Make It Yours window appears.

Configure an Existing Microsoft Account

A To create a new Microsoft account, you can click Create one and then skip to the next subsection, “Configure a New Microsoft Account.”

1 Type your email address.

2 Type your password.

3 Click Sign in.

4 To finish configuring your existing account, skip to the subsection “Complete the Account.”

The Let’s Create Your Account window appears.

Configure a New Microsoft Account

1 Type your name.

2 Type the email address you want to use and select either outlook.com or hotmail.com from the list.


4 Select your country.

5 Type your date of birth.

6 Click Next.

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Yes, you can. Windows does not require that you use an Outlook.com email address from Microsoft, but you can use such an address if you do not want to use an existing address. In the Let’s Create Your Account window, click the Get a new email address link and then type the username you want to use with Outlook.com. Your new address will be [email protected].

continued

http://www.outlook.com

http://www.hotmail.com

http://www.outlook.com

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Complete the Account

Windows asks how you want to receive your security code to verify your account.

1 Click Next.

The Add Security Info window appears.

7 Select your phone number’s country code.

8 Type your mobile phone number.

9 Click Next.

Switch to a Microsoft Account (continued)

How you proceed after you type your email address depends on whether you are creating a new Microsoft account or using an existing account. Using a Microsoft account with Windows can help if you forget your account password and cannot log in.

You can provide Microsoft with your mobile phone number, so if you ever forget your password, Microsoft will send you a text message to help you reset your password. You can also give Microsoft an alternative email address, or you can provide the answer to a secret question.

Switch to a Microsoft Account (continued)


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1

Windows asks if you want to use a PIN with your account.

4 Click Skip this step.

Note: See the section “Set Up a Fingerprint Sign-In” in Chapter 11 to learn how to add a PIN to your account.

Windows connects the Microsoft account to your user account.

The next time you start Windows, you can use your Microsoft account email address and password to sign in.

Windows asks you to verify your current account password.


3 Click Next.

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The Windows Store appears.

3 Use these tabs or the Search box to locate the app you want to install.

4 Click the app from the results that appear.

Install from the Windows Store

1 Click Start ( ).

2 Click Store.

A You might also be able to click the Store icon in the taskbar.

Note: You need a Microsoft account to install from the Windows Store, as described in the previous section, “Switch to a Microsoft Account.”

Install an App

If Windows does not come with an app that you need, you can obtain the app and then install it on your computer. How you start the installation process depends on whether you obtained the app from the Windows Store that comes with Windows

or you downloaded the app from the Internet. If you purchased the app from a retail store and received a physical copy of the software, you install the app using the CD or DVD disc that comes in the package.

Install an App


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15 Click Free.

If the app is not free, click the price button instead, type your Microsoft account password, and then click OK.

Windows installs the app.

Install a File Downloaded from the Internet

1 Click File Explorer ( ).

2 Click Downloads.

Note: If you saved the downloaded file in a folder other than Downloads, use File Explorer to find the downloaded file. To view a file with File Explorer, see Chapter 10.

The Downloads folder appears.

3 Double‐click the file.

The software’s installation app begins.

Note: For compressed files, extract the files and then double‐click the setup file. See Chapter 10 for more information.

4 Follow the installation instructions the app provides.

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or serial number?Look for a sticker attached to the back or inside of the CD case. Also look on the registration card, on the CD, or on the back of the box. If you downloaded the app, the number should appear on the download screen and on the email receipt you receive.

How do I install software from a CD or DVD?Insert the disc and, when the AutoPlay dialog box appears, click Run file, where file is the name of the installation app (usually SETUP.EXE). Then follow the installation instructions the app provides (these installation steps vary from app to app).

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The app runs.

D To close an app, you can click Close ( ) or press + .

Using the Start Menu

1 Click Start ( ).

A Your most frequently used apps appear here.

B Common Windows features appear here.

C The right side of the Start menu displays tiles for commonly used apps.

2 Click the app you want to start.

Start an App

To perform tasks of any kind in Windows, you can use one of the apps installed on your computer. The application you use depends on the task you want to perform. For example, if you want to surf the World Wide Web, you use a web browser application, such as the Microsoft Edge app that comes with Windows.

Before you can use an application, however, you must first tell Windows which application you want to run. You can start an app either from the Start menu or from the All Apps list.

Start an App

D


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E After you click All Apps, the name changes to Back.

3 Click the icon for the program you want to launch.

F If your program icon is in a submenu, click the submenu and then click the program icon.

Windows launches the app.

Using the All Apps List

1 Click Start ( ).

2 Click All apps.

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A tile is a method for displaying a shortcut that launches an app. Many tiles are live, which means that a tile’s text changes to display the app’s most recent information, such as the latest news or your most recently received email messages. See the section “Pin an App to the Start Menu” in Chapter 2 to learn how to add your own Start menu tiles.

Is there an easier way to locate an app?Yes, you can perform a search to locate it. Click inside the taskbar’s Search box and then begin typing the name of the app. As you type, Windows displays a list of apps and other items that match the characters. When you see the app you want, click it to run the program.

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B Windows brings the program’s window to the foreground.

Note: You can also switch to another window by clicking the window, even if it is in the background.

Switch Apps Using the Taskbar

1 Move the mouse ( ) over the taskbar button of the program you want to switch to.

A Windows displays a thumbnail version of the app window.

2 Click the app’s taskbar button.

Note: A program does not have to be minimized to the taskbar for you to use the program’s taskbar button.

Switch Between Running Apps

If you plan on running multiple applications at the same time, you need to know how to easily switch from one application to another. In Windows, after you start one application, you do not need to close that application before you open another one. Windows supports a feature called multitasking,

which means running two or more applications at once. For example, you might keep your word processing application, your web browser, and your email application open all day. You can switch from one program to another using either the taskbar or the keyboard.

Switch Between Running Apps


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C Windows displays thumbnails for each running program.

2 Click the thumbnail of the program you want to switch to.

Windows switches to the program.

Switch Apps Using Task View

1 In the taskbar, click Task View ( ).

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apps using the keyboard?Press and hold and then press to see thumbnail versions of the open windows. Press until the window you want to work in is selected and then release .

Is there an easy way to arrange windows so they do not overlap?Yes, you can snap windows into place. To snap a window to the left half of the screen, drag the top of the window until the mouse ( ) hits the left edge of the screen, and then release. Similarly, drag a window to the right edge to snap it to the right. To snap a window to a quarter of the screen, drag the window to any corner.

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The Windows Store app appears.

A This number tells you how many updates are available.

3 Click Updates ( ).

1 Click Start ( ).

2 Click Store.

Update an App

You can ensure that you are using the latest version of an app by using the Windows Store to install an available update. After a software company releases an app, its programmers continue to work on it. They add new features, improve existing features, fix problems, and close security holes.

After fully testing these improvements and fixes, they place the new version of the app in the Windows Store, which alerts you that an update is available. You can then install the new version.

Update an App


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B If you prefer to update all the apps at once, click Update all and skip step 5.

5 Click Update ( ).

Windows installs the app updates.

The Windows Store displays a list of the available updates.

4 To ensure that you are seeing all the available updates, click Check for updates.

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By default, Windows is configured to automatically check for updated system files each day. If updates are available, Windows downloads and installs them. If you know of an important update, you can check for it manually if you would rather not wait for the automatic check. Click Start ( ) and then click Settings to open the Settings app. Click Update & security and then click Check for updates.

Can I automate the updates?Yes. Instead of updating your apps manually, configure Windows to update the apps automatically. In the Store app, click your user icon, click Settings, and then click the Update apps automatically switch to On.

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If you have an app that you no longer use, you can free up some hard drive space and reduce clutter on the Start screen by uninstalling that app. When you install an app, the program stores its files on your computer’s hard drive, and although most programs

are quite small, many require hundreds of megabytes of hard drive space. Uninstalling an app you do not need frees up the hard drive space it uses and removes its tile (or tiles) from the Start screen (if it has any there) and the Apps screen.

Uninstall an App

Windows asks you to confirm.

5 Click Uninstall.

Windows removes the app.

Uninstall via the Start Menu

1 Click Start ( ).

2 Use the Start menu or the All Apps list to locate the app you want to uninstall.

3 Right‐click the app.

4 Click Uninstall.

Uninstall an App


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The Programs and Features window appears.

3 Click the app you want to uninstall.

4 Click Uninstall (or Uninstall/Change).

The app’s uninstall procedure begins.

5 Follow the instructions on the screen, which vary from app to app.

Uninstall via Programs and Features

1 Type uninstall.

2 Click Change or remove a program.

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Automatic and a Custom uninstall?The Automatic uninstall requires no input from you. It is the easiest, safest choice and therefore the one you should choose. The Custom uninstall gives you more control, but it is more complex and suitable only for experienced users.

How can I uninstall the app that is taking up the most space?Click Start ( ) and then click Settings to open the Settings app. Click System and then click Apps & features to see a list of apps sorted by size. To remove an app, click it, click Uninstall, and then click Uninstall when Windows asks you to confirm.

Working with FilesThis chapter shows you how to work with the files on your computer. These easy and efficient methods take you through all the basic file tasks, including how to view, select, copy, move, and rename files. You also learn how to delete files, as well as how to restore accidentally deleted files. This chapter also covers adding files to your online OneDrive, how to extract files from a compressed folder, and how to specify a different program when you open a file.

CHAPTER 10

Select a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .222

Change the File View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .224

Preview a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .225

Copy a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226

Move a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .227

Rename a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .228

Create a New File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229

Delete a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .230

Restore a Deleted File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .231

Add a File to Your OneDrive . . . . . . . . . . . . . . . . . . . . . . . . . . . . .232

Extract Files from a Compressed Folder . . . . . . . . . . . . . . . . . . . .234

Specify a Different Program When Opening a File . . . . . . . . . . . . .236

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Select Multiple Files

1 Open the folder containing the files.

2 Click the first file you want to select.

3 Press and hold and click each of the other files you want to select.

Select a Single File

1 Click File Explorer ( ).

2 Open the folder containing the file.

3 Click the file.

Select a File

Before you can use File Explorer to do any work with one or more files, you first have to select the files so that Windows knows which ones you want to work with. For example, before you can move files to a new location, you must first select the files you want

to move. You can select just a single file, two or more files, or group of files, or all the files in a folder. Although you learn specifically about selecting files in this section, the technique for selecting folders is exactly the same.

Select a File

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10

Select All Files


2 Click the Home tab.

3 Click Select all.

Note: A quick way to select all the files in a folder is to press

+ .

A File Explorer selects all the files in the folder.

Select a Group of Files


2 Position the mouse ( ) slightly above and slightly to the left of the first file in the group.

3 Click and drag the mouse ( ) down and to the right until all the files in the group are selected.

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Depending on the situation, there are a few ways to deselect files:

• To deselect a single file from a multiple‐file selection, press and hold and click the file you want to deselect.

• To deselect all files, either click the Home tab and then click Select none, or click an empty area within the folder.

• To reverse the selection — deselect the selected files and select the deselected files — click the Home tab and then click Invert selection.

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You can configure how Windows displays the files in a folder by changing the file view. This enables you to see larger or smaller icons or the details of each file.You can choose a view such as Small Icons to see more files in the folder window. A view such as Large

Icons or Extra Large Icons enables you to view images as thumbnail versions of each picture. If you want to see more information about the files, choose either the Tiles view or Details view.

1 In File Explorer, open the folder containing the files you want to view.

2 Click the View tab.

3 In the Layout section, click More ( ).

Windows displays the Layout gallery.

4 Click the view you want.

A File Explorer changes the file view (this example shows Tiles view).

Change the File View

Change the File View

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10Preview a File

1 In File Explorer, open the folder containing the file you want to preview.

2 Click the View tab.

3 Click Preview pane.

A The Preview pane appears.

4 Click a file.

B The file’s contents appear in the Preview pane.

C You can click and drag the left border of the Preview pane to change its size.

Note: When you are finished with the Preview pane, you can click Preview pane on the View tab to close it.

Windows enables you to view the contents of some files without opening them. This makes it easier to select the file you want to work with because it means you do not have to run an application to see

the file’s contents. Previewing the file is faster and uses fewer system resources. Windows previews only certain types of files, such as text documents, rich text documents, web pages, images, and videos.

Preview a File

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5 Open the location you want to use to store the copy.


7 Click Paste.

A Windows inserts a copy of the file in the location.

1 In File Explorer, open the folder containing the file you want to copy.

2 Select the file.


4 Click Copy.

Windows places a copy of the file in a special memory location called the Clipboard.

Copy a File

You can use Windows to make an exact copy of a file. This is useful if you want to back up an important file by making an extra copy on a flash drive, memory card, or other removable disc. Similarly, you might require a copy of a file if you want to send the

copy on a disc to another person. This section shows you how to copy a single file, but the steps also work if you select multiple files. You can also use these steps to copy a folder.

Copy a File

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10Move a File

1 In File Explorer, open the folder containing the file you want to move.

2 Select the file.


4 Click Cut.

Windows places the file in the Clipboard.

5 Open the folder to which you want to move the file.


7 Click Paste.

A Windows moves the file to the new location.

When you need to store a file in a new location, the easiest way is to move the file from its current folder to another folder on your computer. When you save a file for the first time, you specify a folder on your PC’s hard drive. This original location is not

permanent; you can move the file to another location on the hard drive. This section shows you how to move a single file, but the steps also work if you select multiple files or move a folder.

Move a File

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1 In File Explorer, open the folder that contains the file you want to rename.

2 Click the file.


Note: In addition to renaming files, you can also rename any folders that you have created.

4 Click Rename (or press ).

A text box appears around the filename.

Rename a File

You can change the name of a file, which is useful if the current name of the file does not accurately describe the file’s contents. By giving your document a descriptive name, you make it easier to find the file later.

Make sure that you rename only those documents that you have created or that someone else has given to you. Do not rename any of the Windows system files or any files associated with your programs, or your computer may behave erratically, or even crash.

Rename a File

5 Type the new name you want to use for the file.

Note: If you decide that you do not want to rename the file after all, press to cancel the operation.

Note: The name you type can be up to 255 characters long, but it cannot include the following characters: < > , ? : " \ *.

6 Press or click an empty section of the folder.

The new name appears under the file’s icon.

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10Create a New FileYou can quickly create a new file directly within a file folder. This method is faster, and often more convenient, than running a program’s New command. In Windows, you can create several different file types, such as a Bitmap Image (a drawing), Rich Text Document (a WordPad file), Text Document

(a Notepad file), and Compressed (Zipped) Folder (which combines multiple files in a single file, as described in the section “Extract Files from a Compressed Folder,” later in this chapter). You can also create a new folder.

1 In File Explorer, open the folder in which you want to create the file.


3 Click New item.

4 Click the type of file you want to create.

A If you click Folder, Windows creates a new subfolder.

Note: The New Item menu on your system may contain more items than you see here because some programs install their own file types.

B An icon for the new file appears in the folder.

5 Type the name you want to use for the new file.

6 Press .

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1 In File Explorer, open the folder that contains the file you want to delete.

2 Click the file you want to delete.

Note: If you need to remove more than one file, select all the files you want to delete.

Note: See the section “Select a File,” earlier in this chapter, to select multiple files.


4 Click the top half of Delete.

Note: Another way to select the Delete command is to press .

A Windows removes the file from the folder.

Note: Another way to delete a file is to click and drag it to the desktop Recycle Bin icon.

Delete a File

When you have a file that you no longer need, instead of leaving the file to clutter your hard drive, you can delete it. Make sure that you delete only those documents that you have created or that

someone else has given to you. Do not delete any of the Windows system files or any files associated with your programs, or your computer may behave erratically or crash.

Delete a File

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10Restore a Deleted FileIf you delete a file in error, Windows enables you to restore the file by placing it back in the folder from which you deleted it. You can restore a deleted file because Windows stores each deleted file in a

special folder called the Recycle Bin, where the file stays for a few days or a few weeks, depending on how often you empty the bin or how full the folder becomes.

1 Double‐click the desktop Recycle Bin icon.

Note: If you have a touch PC, open File Explorer, tap the first in the address bar, and then tap Recycle Bin.

Restore a Deleted File

The Recycle Bin folder appears.

2 Click the file you want to restore.

3 Click the Manage tab.

4 Click Restore the selected items.

The file disappears from the Recycle Bin and reappears in its original folder.

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Move a File to Your OneDrive

1 In File Explorer, open the folder that contains the file you want to move.

2 Click and drag the file to the OneDrive folder.

A As you drag, if you hover the file over OneDrive, File Explorer expands OneDrive to let you see your other OneDrive folders.

3 Drop the file on the OneDrive folder you want to use.

B File Explorer moves the file to the OneDrive folder.

Add a File to Your OneDrive

If you are using Windows under a Microsoft account, then as part of that account you get a free online storage area called OneDrive. You can use the special OneDrive folder on your PC to move or copy any of your files to your OneDrive. This is useful if you are

going to be away from your computer but still require access to a file. Because the OneDrive is accessible anywhere you have web access, you can view and work with your file without using your computer.

Add a File to Your OneDrive

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10Copy a File to Your OneDrive

1 In File Explorer, open the folder that contains the file you want to copy.

2 Press and hold and then click and drag the file to the OneDrive folder.

C If needed, hover the file over OneDrive to see your other OneDrive folders.

3 Drop the file on the OneDrive folder you want to use.

D File Explorer copies the file to the OneDrive folder.

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Yes. As part of your OneDrive, Microsoft gives you access to the Office Web Apps, which are scaled‐down, online versions of the Microsoft Office applications. To create a document using one of these programs, navigate to your online OneDrive, click Create, and then click Word document, Excel workbook, PowerPoint presentation, OneNote notebook, Excel survey, or Plain text document.

How do I access my OneDrive online?You need to open Microsoft Edge and navigate to the OneDrive site, http://onedrive.live.com. After you are logged in to your OneDrive, you can use it to create new folders, rename files, delete files, and more.

http://onedrive.live.com/

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View Compressed Folder Files

1 In File Explorer, open the folder containing the compressed folder.

A The compressed folder usually appears as a folder icon with a zipper.

2 Double‐click the compressed folder.

Extract Files from a Compressed Folder

If someone sends you a file via email, or if you download a file from the Internet, the file often arrives in a compressed form, which means the file actually contains one or more files that have been compressed to save space. To use the files on your computer, you need to extract them from the compressed file.

Because a compressed file can contain one or more files, it acts like a kind of folder. Therefore, Windows calls such files compressed folders, zipped folders, or Zip archives. You can view these files or extract them from the folder.

Extract Files from a Compressed Folder

B File Explorer displays the contents of the compressed folder.

Note: File Explorer is only displaying the contents of a compressed folder; it has not extracted the files. To extract the files, follow the steps in the next subsection.

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The Select a Destination and Extract Files dialog box of the Extract Wizard appears.

5 Type the location of the folder into which you want to extract the files.

C You can also click Browse and choose the folder.

6 If you want to open the folder into which you extracted the files, click Show extracted files when complete ( changes to ).

7 Click Extract.

Windows extracts the files.

Extract Compressed Folder Files

1 In File Explorer, open the folder containing the compressed folder.

2 Click the compressed folder.

3 Click the Extract tab.

4 Click Extract all.

How can I create a compressed folder?Follow these steps:1 Select the files and folders you

want to store in the compressed folder.

2 Right‐click any selected item.

3 Click Send to.

4 Click Compressed (zipped) folder.

The compressed folder appears.

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236

Windows asks how you want to open this file type.

5 Click More apps.

1 In File Explorer, open the folder that contains the file you want to open.

2 Click the file.

3 Click the Open .

A If the program you want to use appears here, click the program and skip the remaining steps.

4 Click Choose another app.

Specify a Different Program When Opening a File

You can open a file in a different program from the one normally associated with the file. This enables you to use the other program’s features to work on the file.You may have situations where you prefer to open a particular file with a different program. For example,

double‐clicking a picture file opens it in the Photos app. However, you may prefer to open the picture file in Paint or some other image‐editing program so that you can make changes to the picture. This section shows you how to open any document in another program.

Specify a Different Program When Opening a File

Working with Files

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chapter

10 B Windows displays a full list of

programs you can use to open the file.

6 Click the program you want to use to open the file.

C If the program you want to use does not appear in the list, you can click Look for another app on this PC and use the Open With dialog box to specify the program.

7 Click OK.

Windows opens the file in the program you chose.

sim

plif

y it Can I set the default program for multiple

file types?Yes. In the taskbar’s Search box, type set default, click Default Programs, and then click Set your default programs. Click the program you want to use, click Choose defaults for this program, click each file type you want to open with the program ( changes to ), and then click Save.

How can I open every file of the same type in the new program?If you want to open every file of the same type — such as Text Document files or Rich Text Format files — in the same program, follow steps 1 to 6 and then click Always use this app to open .ext files ( changes to ).

Computer Sciences – 2022

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