vedanta
Log inLet’s
(A course in Computer Science)
5Book
Sushil Upreti Authors
Sunil Kumar Gharti
vedanta
Vedanta Publication (P) Ltd.
j]bfGt klAns;] g kf| = ln=
Vanasthali, Kathmandu, Nepal
+977-01-4982404, 01-4962082
[emailprotected]
www.vedantapublication.com.np
vedanta
Log inLet’s
(A course in Computer Science)
5Book
Authors
Sushil Upreti and Sunil Kumar Gharti
All rights reserved. No part of this publication may
be reproduced, copied or transmitted in any way,
without the prior written permission of the publisher.
¤ Vedanta Publication (P) Ltd.
First Edition: B.S. 2077 (2020 A. D.)
Second Edition: B.S. 2078 (2021 A. D.)
Layout and Design
Pradeep Kandel
Printed in Nepal
Published by:
Vedanta Publication (P) Ltd.
jb] fGt klAns];g kf| = ln=
Vanasthali, Kathmandu, Nepal
+977-01-4982404, 01-4962082
[emailprotected]
www.vedantapublication.com.np
PREFACE
This is the age of information. Information Technology has undoubtedly invaded all
walks of life to such an extent that computer and information literacy has become the
fundamental part of our daily activities. Computer Science is now an essential addition
to the school curriculum at all levels.
Vedanta Let's Log in (A course in Computer Science) is a series of ten books on
Computer Science for basic and secondary level students, designed for the need of new
generation to help acquire knowledge on the theory, application and programming
aspects of computing. This series is based on the new syllabus of Computer Science,
designed and approved as per the curriculum prescribed by Curriculum Development
Center, Ministry of Education, Government of Nepal.
The series covers the history of computer, its accessories, applications and programming
in LOGO and QBASIC in a step-by-step and graded manner following logical and
scienti ic approach. Concept of graphic and web design is also illustrated with many
practical examples. This series not only assists the students and the teachers in the
class but also incorporates latest information and developments in IT with the present
need of the students in Nepal. It also provides other enthusiasts and learners with the
skill and knowledge to cope up with the growing demand of IT skills in market and
daily life.
We earnestly hope that the students would ind the journey through this series an
enjoyable experience and gain a sound working knowledge on the basic aspects of
computing and information technology.
As far as possible, we have sincerely put in our efforts to make the book error free.
However, there is always scope for improvement. Constructive criticism and feedback
are always welcome.
Authors
Contents Page No.
Unit Topics 5
15
1. Evolution of Computer 22
2. Types of Computer 28
3. Computer Language 35
4. Computer Software 44
5. Internet and Its Uses 61
6. More on MS– Word 73
7. Doing Calculation in Computer 80
8. Typing Techniques 86
9. Program and Programming Tools 112
10. Programming in Logo
Test paper I - IV
Lesson
1 Evolution of computer
Today, we are living in the age of computer and most of our daily activities
cannot be performed smoothly without using computer. Hence, computer has
become a very important part of our lives. The computer system has undergone
development in different phases and the process of development is still going
on.
Before the invention of computer, our ancestors used stones to count their
belongings. As the counting became more complex and it could not be done
easily with human fingers, people started to develop various types of counting
devices.
Inventions of calculation machines began during the era of early Chinese
Dynasties with the Abacus, which is considered as the first calculating device.
Development of Mechanical Computing Devices
Abacus (Developed by: China, Year 3000 BC)
• Invented around 500 years ago.
• First mechanical calculating device.
• It was made up of a frame divided into two parts:
heaven and earth.
• Each rod in the heaven had 2 beads and the earth
had 5 beads
• It was used for mathematical calculations like addition,
subtraction,multiplication, and division.
Napier's Bones
• Invented by a Scottish mathematician John Napier in 1616 AD.
• It is used for multiplication and division based on the principles of
logarithms.
• Consisted of rectangular strips of rods made of bones and ivory.
• Rods had numbers written on them.
5 vedanta Let's Log in (A course in Computer Science) Book 5
John Napier Napier’s Bones
Slide Rule
William Oughtred Slide Rule
• Slide rule was invented by William Oughtred in 1620 A.D.
• Slide Rule was the first analog device which used the principle of logarithms.
• It could solve simple multiplication and division problems.
• It consisted of two sets of rulers joined together with a marginal space
between them.
Pascaline
Blaise Pascal Pascaline calculator
6
vedanta Let's Log in (A course in Computer Science) Book 5
• Pascaline was invented by Blaise Pascal in 1642 A.D.
• It performed addition, subtraction, multiplication, and division by repeated
addition and repeated subtraction respectively.
• It looked like a rectangular box.
• It consisted of 8 movable wheels.
• Numbers were displayed by rotating the wheels.
• It is also known as adding machine.
Stepped Reckoner Line
Gottfried Wilhelm Von Leibniz Stepped Reckoner
• Stepped Reckoner was invented by Gottfried Wilhelm Von Leibniz, a German
mathematician and philosopher in 1694 A.D.
• It was the first calculator to perform all four of basic arithmetic operations :
addition, subtraction, multiplication, and division.
• It was also known as modified version of Pascaline.
Jacquard's Loom
Joseph Marie Jacquard Jacquard's Loom
7 vedanta Let's Log in (A course in Computer Science) Book 5
• A French inventor, Joseph Marie Jacquard invented an automatic weaving
machine called Loom in 1801 A.D.
• It used punched card for storage of information.
Difference Engine
Difference Engine Charles Babbage
• Difference Engine was developed by Charles Babbage in 1822 A. D.
• It is an automatic mechanical calculating machine.
• It is the earliest automatic calculator.
• It worked with the power of steam.
Analytical Engine
• Analytical Engine was developed by Charles Babbage after
working on the difference engine for 10 years.
• It was first general purpose programmable mechanical
computer.
• It could solve any mathematical problem.
• This device could not be completed due to the lack of
required technologies and funds at the time.
• It was formed the basis of all modern computers.
• Charles Babbage provided the basic concept of computer;
so, he is regarded as the father of modern computer.
Ada Lovelace
Lady Augusta Ada Lovelace was the first computer
programmer. She helped Charles Babbage to write programs
for his Analytical Engine. She developed the first programs for
Analytical Engine in 1848 A.D.. She had suggested Babbage
to use binary number system (0, 1) for programs and data in
vedanta Let's Log in (A course in Computer Science) Book 5 8
his machine. Because of her first idea in the development of programs, she is
honoured as the first Computer Programmer.
Tabulating Machine
Dr. Herman Hollerith Tabulating Machine
• Tabulating Machine was developed by Herman Hollerith, an American
census statistician in the 1890's.
• It is the first electronic machine
• It is capable of reading data, processing it and giving output.
• It used punched cards to give input, output, record, and store information.
• The machine was used by American Department of Census to compile
census record in 1890 A.D.
Development of Electro-Mechanical Computers
Mark-I
Howard H. Aiken Mark-I
• Mark-I was developed by Howard Aiken, Professor at Harvard University in
1944.
• It was the first automatic electromechanical computer developed with the
help of IBM.
• It is marked as the beginning of the era of modern computing.
• It was 15 meters long and wires were used to connect the various parts of the
machine.
9 vedanta Let's Log in (A course in Computer Science) Book 5
ABC (Atanasoff Berry Computer)
John Vincent Atanasoff Atanasoff Berry Computer Clifford Berry
Atanasoff Berry Computer (ABC) was developed by Professor of physics and
mathematics, John Vincent Atanasoff and his assistant Clifford Berry in 1942
A.D. It was the first electronic and digital computer. It had used vacuum tubes
as a main memory and punch cards as secondary memory devices. It introduced
the ideas of binary arithmetic and logic circuit.
Development of Electronic Computers
ENIAC(Electronic Numerical Integrator and Calculator)
John William Mauchly ENIAC (1946 AD) John Presper Eckert
• ENIAC was the first general purpose fully electronic digital computer
developed by John William Mauchly and John Presper.
• It was 1000 times faster than Mark – I
• It consisted of 18000 vacuum tubes
• It weighed about 30 tonnes.
• It did not store programs and it had to be programmed by manual wiring.
vedanta Let's Log in (A course in Computer Science) Book 5 10
EDVAC (Electronic Discrete Variable Automatic Computer)
John Von Newman EDVAC
• EDVAC was developed by John William Mauchly and John Presper Eckert at
Pennsylvania University in 1952 A.D.
• It contained magnetic tape as memory device.
• It included a stored program, a central processor, and a memory for both
data and programs.
• It was based on binary number system. It is known as the first stored program
computer.
• It weighed approx. 8000 Kg.
• It covered an area of 45.5 square meter.
EDSAC (Electronic Delay Storage Automatic Computer)
Maurice Wilkes EDSAC
EDSAC was the first operational stored program computer developed by Professor
Maurice Wilkes at Cambridge University Mathematical Laboratory, England in
1947 A.D. This computer performed its first calculation on May 6, 1949. It was the
world's first stored-program computer to operate a regular computing service.
It contained 3600 vacuum tubes and it required 30 kilowatts of electric power. It
was the first operational stored program electronic computer.
11 vedanta Let's Log in (A course in Computer Science) Book 5
UNIVAC-I (Universal Automatic Computer)
• UNIVAC-I was developed by John William Mauchly
and John J. Presper Eckert in 1951 A.D.
• It was the first commercially available electronic computer.
• It is the First computer to handle both numeric and
text data.
Do you know?
When was the word "computer" was first used?
The word "computer" was first recorded as being used in 1613 and originally
was used to describe a human who performed calculations or computations.
The definition of computer remained the same until the end of the 19th century,
when the industrial revolution gave rise to machines whose primary purpose
was calculating.
IBM's First Computer
On April 7, 1953, IBM publicly introduced the 701, its first commercial scientific
computer.
The first Apple computer
The Apple I (Apple 1) was the first Apple computer that originally sold for
$666.66.
The first IBM personal computer
IBM introduced its first personal computer, the IBM PC,
in 1981. The computer was code-named Acorn.
vedanta Let's Log in (A course in Computer Science) Book 5 12
Main Points to Remember
Computer plays a very vital role in our daily life.
Abacus was the first calculating device developed 500 years ago.
Jaquard’s Loom was one of the first machines that was run by
programs.
Charles Babbage is known as the ‘Father of Computer’.
Augusta Lovelace is known as the first programmer.
Mark-I was the first electro-mechanical computer.
EXERCISE
1.Write either True or False statements:
a) Abacus is a rectangular box divided into two parts by mid bar.
b) Slide rule was invented by John Napier.
c) Pascaline was invented by Blaise Pascal.
d) Dr.Herman Hollerith invented the Analytical Engine.
e) Charles Babbage is regarded as the first computer programmer.
f) Lady Augusta helped Charles Babbage to write programs for his
Analytical Engine.
g) ENIAC was the first operational computer with program stored in it.
h) EDSAC could handle both numbers and alphabets.
2. Fill in the blanks with correct words.
a) ……………….is known as the father of computer.
13 vedanta Let's Log in (A course in Computer Science) Book 5
b) Abacus was the first calculating device invented by the …………… .
c) An abacus is divided into …………….parts.
d) Analytical Engine was developed by …………….. in 1833 A.D.
e) ENIAC contained …………….. vacuum tubes as a main memory.
3. Write the full form of the following:
a) ABC b) ENIAC c) EDSAC
d) EDVAC e) UNIVAC
4. Match the following:
Group "A" Group "B"
a) Difference Engine i) Howard Aiken
b) Napier’s Bones ii) Gottfried Wilhelm Von Leibniz
c) Slide Rule iii) Dr. Herman Hollerith
d) Pascaline iv) John Napier
e) Stepped Reckoner v) Blaise Pascal
f) Mark-I vi) Charles Babbage
g) Tabulating Machine vii) William Oughtred
5. Answer the following:
a) What is abacus?
b) Who invented Napier's Bones?
c) Who is known as the father of modern computer and why?
d) Why is Lady Augusta Ada known as the first computer programmer?
e) Who developed ABC?
vedanta Let's Log in (A course in Computer Science) Book 5 14
Lesson
2 Types of Computers
Introduction
A computer is an electronic device that process data, converting it into
information useful to people. There are two basic types of computer: Analog
and Digital. The computers commonly used today are all digital computers.
Computer can be categorized in several ways. For example, some computers
are designed for use by one person; some are meant to be used by groups of
people; and some are not used by people at all. They can also be categorized
on the basis of their power. Within a single category, computers may be
subcategoried on the basis of price, the types of hardware they contain, the
kinds of software they can run, and so on.
Computers for Individual Users
Most computers are meant to be used by only one person at a time. Such
computers are often shared by several people (such as those in your school’s
computer lab), but only one user can work with the machine at any given
moment. The six primary types of computers in this category are:
• Desktop
• Workstations
• Notebook computers
• Tablet computers
• Handheld computers
• Smart phones
These systems are all examples of personal computers (PCs), a term that
refers to any computet system designed for use by a single person. Personal
computers are also called microcomputers because they are among the
smallest computers created for people to use.
15 vedanta Let's Log in (A course in Computer Science) Book 5
Desktop Computers
The most common type of personal computer is the
desktop computer, a PC that is designed to place on
(or under) a desk or table. These are the systems we
see all around us, in schools, at home, and in offices.
Today’s desktop computers are far more powerful than
those a few years ago. They are used for many tasks,
like communication, music production, photographs
and videos editing, play sophisticated games, and the
like.
Work Stations
A workstation is a specialized, single-user computer
that typically has more power and features than a
standard desktop PC. These machines are popular
among scientists, engineers, and animators who need
a system with greater than average speed.
Notebook Computers
Notebook computers, as their name implies,
approximate the shape of an 8.5 by 11 inch notebook
and easily fit inside a briefcase. Because people
frequently set these devices on their lap, they are also
called laptop computers. Notebook computers can
operate on alternating current or special batteries.
Notebooks are fully functional microcomputers; the
people who use them need the power of a full-size
desktop computer wherever they go. Because of
their portability, notebook computers are also called
mobile computers.
Tablet Computers
The tablet computer is the newest development in portable, full-featured
computers. Tablet PCs offer all the functionality of notebook PC, but they are
vedanta Let's Log in (A course in Computer Science) Book 5 16
lighter and can accept input from a special pen called
a stylus or a digital pen used to tap or write directly
on the screen. Many tablet PCs also have a built-in
microphone and special software that accepts input
from the user’s voice.
Handheld Computers
Handheld personal computers are computing devices
small enough to fit in your hand. A popular type of
handheld computer is a personal digital assistant
(PDA). Most PDAs come with a pen that lets the user
write on the screen. It allows the user to access the
Internet through a wireless connection, and several
models offer features such as cellular telephones,
cameras, and music players.
Smart Phones
A smartphone is a mobile phone with an integrated
computer and other highly advanced features. A
typical smartphone has a high-resolution touch
screen display, digital camera, music players, WiFi
connectivity, Web browsing capabilities, and the
ability to accept sophisticated applications.
Computers for Organization
Some computers handle the needs of many users at the same time. These
powerful systems are most often used by organizations, such as businesses or
schools, and are commonly found at the core of the organization’s network.
Mainframe Computer
Mainframe computers are used in large organizations,
such as insurance companies and banks, where
many people frequently need to use the same data.
Mainframes are large, powerful systems. The largest
mainframes can handle the processing needs of
17 vedanta Let's Log in (A course in Computer Science) Book 5
thousands of users at any given moment.
You may have interacted with a mainframe system without even knowing it.
For example, if you have ever visited an airline’s web site to reserve a seat on a
flight, you probably conducted a transaction with a mainframe computer.
Mini computer
First released in the 1960s, minicomputers got
their name because of their small size compared
to other computer of the day. The capabilities of
minicomputers are somewhere between those of
mainframes and personal computers. For these
reasons, minicomputers are often called midrange
computers.
Like mainframes, minicomputers can handle much more input and output than
personal computers can. Although some “minis” are designed for a single user,
the most powerful minicomputers can serve the input and output needs of
hundreds of users at a time. Users can access a central minicomputer through
a terminal or a standard PC.
Supercomputer
Supercomputers are the most powerful computers made, and they are
physicallysome of the largest. These systems can process huge amount of
data, and the fastest supercomputers can perform more than one trillion
calculations per second. It contains several processors that work together to
make it most powerful and fastest computer. It has a large memory capacity
and high processing speeds for solving scientific and engineering problems. It is
mainly used to forecast the weather and global climates, biomedical research,
aircraft design, robots design, military research, and other areas of science and
technology.
vedanta Let's Log in (A course in Computer Science) Book 5 18
Main Points to Remember
There are two basic types of computers: analog and digital.
The computers commonly used today are all digital computers.
Computers designed for use by a single person include desktop
computers, notebook computers, tablet computers, handheld
computer, and smart phones.
The terms personal computer (PC) and microcomputer can refer to any
computer meant for use by a single person.
The desktop computer is the most common type of personal computer.
A workstation is a specialized, single-user computer that typically has
more power and features than a standard desktop PC.
Notebook computers are full-featured PCs that can easily be carried
around.
Mainframes, minicomputers, and supercomputers are commonly used
by organizations and support the computing needs of many users.
Supercomputers are the largest and most powerful computers made.
19 vedanta Let's Log in (A course in Computer Science) Book 5
EXERCISE
1. Write either True or False.
a) Digital computer uses binary digits '0' and '1' for its
operations.
b) Personal Computers are also called supercomputers.
c) Notebook PCs fall into a category of devices called
mobile computers.
d) Minicomputer is mainly used as a server in computer
network.
e) Mainframe computer is the powerful single user
computer.
f) Supercomputer is mainly used to forecast the
weather and global climates.
2. Fill in the blanks.
a) There are two basic types of computers: …………. and ………..
b) The most common type of personal computer is the …………………
computer.
c) Notebook computers are also called ………………..computers.
d) Tablet computers accept input from a special pen called a ………….or a
………
e) A smartphone is a………..phone.
f) Mainframe computers are used in …………..organizations.
vedanta Let's Log in (A course in Computer Science) Book 5 20
g) Minicomputers are often called……………....computers.
h) Supercomputers are the most ……………..…computers made.
3. Answer the following.
a) What is computer?
b) List six types of computers designed for use by a single person.
c) Why are notebook computers also called mobile computers?
d) What is a personal computer? What are its main uses?
e) Write the uses of mainframe computer.
f) What are the supercomputers and where are they used?
g) Describe four features you expect to find on tablets and smartphones.
h) Choose suitable devices for each of the following applications. In each
case, give a reasons for your choice .
(i) A report 'in the field' sending data back immediately to head office.
(ii) A person wishing to monitor their health/exercises while 'on the go'
wherever they are.
21 vedanta Let's Log in (A course in Computer Science) Book 5
Lesson
3 Computer Language
If people want to talk to each other, they need a common language that both
parties can understand. If one person speaks Nepali and other person speaks
English, Chinese or Hindi, they do not understand each other’s language. How
will they communicate? They need an interpreter who can interpret for both of
them. It is same with us and computers.
Computer Language
A computer language or programming language is a vocabulary and set of
grammatical rules for instructing computer or computing device to perform
specific tasks. A program is written in specific language that computer can
understand and interpret. This language is called computer language or
programming language.
As we know, computer is a machine that works
on electricity. Depending upon the two states of
electricity (presence or absence of electrical pulse), a
computer can understand only binary language that
is the language of zeros (0's) and ones (1's). In the
beginning, programs were written only in machine
language, since it was the only language understood
by the computer.
Some of the most commonly used programming languages are C, C++, Java,
Python, PHP, etc.
vedanta Let's Log in (A course in Computer Science) Book 5 22
Types of Computer Language • High Level Language
There are three types of computer languages:
• Machine Language • Assembly Language
Machine Language
The lowest and the most basic form of computer language
is the machine language. Information is entered into the
computer in the form of 1's or 0's. Binary instructions are
the equivalent to the on/off signals used by computers to
carry out operations. These codes can be easily interpreted
by computer. The main benefit of machine language is that the code can be
written by a user very fast and efficiently, since it is directly executed by the
CPU. However, the machine language is a lot more difficult to learn and to edit
if errors occur.
Assembly Language
Coding a program in binary form
was very tedious. To overcome the
difficulties of writing machine codes,
assembly languages were developed.
These languages use mnemonic codes
to write any instruction. A mnemonic
is a short name given to an instruction
like MOV (move), INT (interrupt), A
(add), CMP (compare), MP (multiply), STO (store).
The program written in assembly language has to be translated into machine
language. Then, it can be executed by computer. This translation is done by a
computer program referred to as Assembler.
23 vedanta Let's Log in (A course in Computer Science) Book 5
High Level Language
High level languages use English language
words to give instructions to computer. A soft-
ware program called Interpreter is used to
translate English language into machine lan-
guage that computer can understand. Nowa-
days, normally programs are written in High
level language. Some examples of High level
languages are C, C++, JAVA, Python, and PHP,
etc.
Advantages of High Level languages
• Much easier to understand and learn.
• Easier for program debugging.
• Require less time to write.
Some Important Terms and Definitions
Program
The set of instruction given to computer in a computer language is called a
computer program.
Programmer
A person who writes computer software by using one or more computer lan-
guages is called a programmer or developer or coder.
Software
It is a set of program, which enables the computer to obtain the solution of a
problem.
vedanta Let's Log in (A course in Computer Science) Book 5 24
Language processor
Language processor is a software that translates programs written in any other
languages into machine language.
Assembler
It is a program, which is used to translate programs written in assembly language
into machine code.
Compiler
A compiler translates a program written in high level language to executable
machine language program, i.e., the object program. The object program is
generated and executed to get the desired result.
Interpreter
An interpreter is a type of language translator that translates program written
in high level language (human language) into machine language line by line or
statement by statement.
25 vedanta Let's Log in (A course in Computer Science) Book 5
Main Points to Remember
A program is a set of instructions given to the computer to accomplish
a certain task.
A programming language is a computer tool that allows a programmer
to write commands.
A computer can understand only binary language that is the language
of zeros and ones (0's a1's).
Binary language is also known as machine language.
There are three types of computer languages: Machine Language,
Assembly Language, and High Level Language.
A mnemonic is a short name of given to instruction in assembly
language.
Assembler is the software program that translates assembly language
into machine language.
High level languages use English language to give instructions to the
computer.
A compiler translates a program written in high level language to
executable machine language program.
EXERCISE
1. Fill in the blanks.
i. The ………………………translator converts an assembly
language into a machine language.
ii. A computer can understand only ……………….language.
vedanta Let's Log in (A course in Computer Science) Book 5 26
iii.Program is a set of …………………given to a computer in a
computer language.
iv.Binary language is also known as …………….language.
2. Write True or False.
a. Assembler is a software program which is used to
translate programs written in assembly language into
machine language.
b. High level languages use Nepali language to give
instructions to the computer.
c. C, JAVA, and Python are the examples of high level
language.
d. A compiler translates a program written in low level
language to executable machine language program.
3. Answer the following.
a.What is computer language?
b.What are the three types of computer language?
c. What is a language processor?
d.What is program and programmer?
Activities
a. Find out the computer languages installed in the computer
in your computer lab.
27 vedanta Let's Log in (A course in Computer Science) Book 5
Lesson
4 Computer Software
Software
Computer is a machine that cannot
work on its own as it does not possess
any intelligence. It needs the help
of hardware and software to work.
Computer hardware is just like the
engine while the software is like the fuel
that allows or energizes the engine to
operate. While using computer, we can
touch the monitor but we cannot touch
the things or pictures displayed on the monitor. As we cannot touch them, they
are not part of the computer hardware. They are called computer software.
Without software, the hardware is useless. The computer works according to
the set of instructions given to it. These ordered set of instructions are called
Programs. These programs are written in computer programming languages.
Software is a collection of programs stored and run on computer hardware.
It helps users to work on computer. Software is the part of computer which
cannot be touched or seen.
The computer hardware such as microprocessor,
RAM, and motherboard cannot work without
software. They require a proper set of instructions
to work.
Software are of two types: System software and
Application software.
System Software
The system software is a set of one or
more programs that directs the internal
operation of the computer system such
as reading data from input devices,
transmitting processed information to
vedanta Let's Log in (A course in Computer Science) Book 5 28
output devices, checking system components, converting data/instructions to
computer in the form it understands.
Operating system
Operating system is one of the system softwares that provides a working
environment for the users, and manages and controls the hardware. It also
works as an interface between user and computer. Some examples of operating
system software are DOS, Linux, Microsoft Windows, Apple macOS, Chrome
OS, Android, and Apple iOS.
The main functions of an operating system are:
• Input / Output Management: It controls the working of all input and output
devices.
• Memory Management: It assigns memory to various programs whenever
required and also frees the memory when it is not in use.
• Processor Management: It manages the working of the processor by
allocating different jobs to it.
• File Management: It keeps track of information relating to creation,
deletion, transfer, copy, and storage of files in a systematic way.
• Software Execution: It runs the application software like Paint, MS-Office,
etc.
• Security: It provides security by means of passwords or fingerprints to
prevent misuse of a PC.
29 vedanta Let's Log in (A course in Computer Science) Book 5
As soon as we switch ON the computer, the Operating System (OS) starts
loading. After the OS is loaded, desktop appears on screen.
Here, the screen of Windows 10 is given when it gets loaded. Now the computer
is ready to take instructions from user.
Icons
Desktop
Taskbar
Language Processor
Software is created by writing programs in computer languages. There are many
computer languages, such as Qbasic, C, C++, Java, and Python. The programs
written in these languages cannot be understood by a computer directly. A
computer is an electronic machine and it can only understand the machine
language which comprises ‘0's’and ‘1's’. A language processor is a very important
software as it translates or converts program written in a computer language
into machine languages to make it possible for computer to understand it.
vedanta Let's Log in (A course in Computer Science) Book 5 30
Utility Software
Utility software is a system software that
analyses and maintains computer. This
software focuses on how OS works. It
performs task to enable smooth functioning
of computer. This software may come along
with OS like windows defender, windows
disk cleanup tool, antivirus, backup software, file manager, disk compression,
etc.
Application Software
This type of software is designed to do specific tasks for users. This software
is used to fulfil the user requirements, such as preparing official letters,
designing posters, handling calculations and figures, financial accounting, result
preparation, billing, etc.
Microsoft Word, Microsoft Excel,Adobe Photoshop, MS-Access, MS-PowerPoint,
and Windows Media Player are a few examples of application software.
The background picture of Windows desktop is called desktop background. It is
also called wallpaper. Desktop wallpaper is the image that fills the background
of our computer screen when all programs are closed.
31 vedanta Let's Log in (A course in Computer Science) Book 5
Main Points to Remember
Software is a collection of programs that are stored and run on the
computer hardware.
There are two types of software: Application and System software.
System software directs the internal operation of computer system.
An Operating System Software governs all the hardware and software
components of computer.
A language processor is a software that translates or converts a
program written in a computer language into machine language.
Utility software is designed to help, analyse, configure, optimise or
maintain a computer.
Application software performs the tasks for users.
Operating System (OS) provides a working environment for users.
vedanta Let's Log in (A course in Computer Science) Book 5 32
EXERCISE
1. Write T for true and F for the false statements.
a) Software is of three types.
b) Software controls the internal computer operations.
c) Operating system is an interface between the user and the
computer.
d) Microsoft Word is an example of application software.
e) Qbasic, C, and Python are the examples of utility software.
f) We cannot touch computer software.
g) Disk cleanup is a utility software.
2. Fill in the blanks with correct words given.
a) Windows 10 is an ……………software.
b) …………………. is loaded when computer is switched ON.
c) Small pictures on the desktop are known as …………………. .
d) Software that is designed to do specific tasks for users is called
………………….
3. Answer the following questions.
a) What is computer program?
b) What is computer software?
c) Mention the different types of software with examples.
d) Define system software and application software.
e) What is an Operating System? Briefly explain any two of its functions.
f) Make a list of computer software you have used so far.
33 vedanta Let's Log in (A course in Computer Science) Book 5
4. Match the following. i) word processing software
a) Winzip ii) Programming language
b)MS-Word iii) Compression
c) Photoshop iv) Graphics Software
d)MS-Excel v) Electronic spread sheet
e)Python vi) DBMS
Activities
1. Find out the operating system and the antivirus being used in
computer at your home and in school. Now with the help of teacher,
use the anti-virus software to scan computer system for virus.
2. Given below is a list of software. Classify them under the appropriate
columns. [Excel, Word, Windows 10, Disk Cleanup, Linux, iOS]
Operating System Utility Software Application Software
3. Go to your computer lab and with the help of your teacher, use the
following Utility Software.
a)Disk Cleaner b) Disk Defragment c) Antivirus
vedanta Let's Log in (A course in Computer Science) Book 5 34
5Lesson Internet and its
Uses
Introduction
InternetstandsforINTERconnectedNETwork.
It is a huge network of computers around
the world. Millions of computers are
connected all over the world through the
internet. These computers are connected to
one another using telephones lines, cables
,or some other means.
The computers may be present in different places or even in different countries.
Being a part of this huge network lets you exchange your information and ideas
with millions of other people, who are connected with this network. So, it is
known as network of networks (NET).
History of Internet
Internet was firstly known as ARPANET (Advanced Research Project Agency
Network). It was introduced by the Department of Defense (DOD) of the United
States of America in 1969. Later on, ARPAnet was connected with different
universities and other network of the USA. The main purpose behind connecting
ARPANET with other universities and networks was to share information on
research and development in scientific and military fields. It was big success to
make it available commercially to the people with a new name Internet in 1995.
Uses of Internet
Internet has completely changed the way we communicate with each other
and live our lives. Some important and most common uses of internet are as
follows:
a) News
b) Electronic Mail
c) Online Chat
d) Online Shopping
e) Online Banking
35 vedanta Let's Log in (A course in Computer Science) Book 5
f) Uploading Data
g) Downloading Data
h) Communities
News
On internet, we can get the latest news and other happenings any time from all
corners of the world.
E-mail or Electronic mail is one of the most popular services provided by the
internet. E-Mail is the system of sending and receiving electronic messages
from one computer to another through internet. E-mail is the important
communication tool for keeping in touch with family, friends and organizations
Benefits of communicating through emails.
i. It is the fastest way of sending and receiving messages.
ii. We can send a message to more than one recipient at the same time.
iii. It is an inexpensive way of communication. It costs even less than a
phone call.
iv. E-mail allows us to exchange messages in the form of text, images, and
videos.
The advantages of email as compared to postal services are as follows:
i. It is very fast.
ii. It is the cheapest communication system.
iii. The physical presence of the concerned recipient is not required.
iv. Same message can be sent to different persons.
v. It can be accessed from any part of the world in a computer.
vi. It can be sent and received at any time.
vedanta Let's Log in (A course in Computer Science) Book 5 36
Online Chat
Online chat is one of the important uses of internet.
It allows people to communicate with each other in
real-time. It supports people at different locations
to send and receive both text and voice messages
instantly. Online chat can be used to meet new
people, make new friends, and stay in touch with old
friends.
Online Shoping
We can purchase various items like books, clothes,
gift items, etc. from different shops around the world
without actually going there.
Online Banking
Now, all banking operations can be done right from
our home or office using internet.
Downloading Data
The system of transfering the file, data, program, etc. from a host
computer (server) to user’s computer is known as downloading.
We can download different games, songs, videos, movies, software,
files, information, etc. from internet.
Uploading data
Uploading is the important service of internet. The system of
copying data, file, or program from user's computer to internet
server is known as uploading. This process is generally used when
you want to send pictures, articles, or files to your family, friends,
or other or organizations.
Communities
Forming communities is also an important use of
internet. A community is a great forum on Internet to
meet up with people having similar interests. Social
networking sites where people can interact with their
family and friends at a single place are examples of
online communities.
37 vedanta Let's Log in (A course in Computer Science) Book 5
Important Terms used on the Internet
World Wide Web (www)
World Wide Web (www) is the most widely used and the most popular service
on internet. It contains millions of websites that provide information in the form
of text, animation, pictures, and videos. The information stored and displayed
on internet by www is in the form of electronic page and it is called web page.
Web Server
Web server is a computer on
internet that stores web pages.
Clients are like out-computers,
who access the information from
servers.
URL
Every web page has a unique address, called a URL
(Uniform Resource Locator). You can quickly access a
web page if you know the address of the web page.
A web page URL starts with http (Hyper Text Transfer
Protocol) and contains the computer name, directory
name, and name of the web page.
Web browser
Web browser is a software or program that
accesses web pages and displays them on user’s
computer. It also allows user to retrieve, view,
and copy information using internet. Google
Chrome, Brave,Mozilla Firefox, Internet Explorer,
Safari, Opera mini, etc. are common examples of
web browsers.
vedanta Let's Log in (A course in Computer Science) Book 5 38
Webpage
Webpage is a page of information on Internet about a particular subject. It
can be accessed through a web browser and displayed on a computer screen
using web browser. A webpage may have many hyperlinks to open other linked
pages.
Home Page
The main or first page of a
website is known as home
page. It gives detailed
information on its owner and
provides links to other pages.
The home page is the address
of a file that automatically loads when a web browser starts. It is also known as
index page.
Hyperlinks
Hyperlink is the highlighted text on a web page, which on clicking connects to
other pages on the web. Generally, a website consists of number of web pages
linked to one another by hyperlinks. These hyperlinks are highlighted either by
underlining the text or by displaying them in different colors, or both. When
the mouse pointer is moved to hyperlink, the shape of the cursor changes from
arrow symbol to handy symbol.
39 vedanta Let's Log in (A course in Computer Science) Book 5
Search engine
Search engine is the website that allows the users
to search information based on a keyword or
combinations of keywords in different subjects and
topics. Some of the search engine websites are:
www.google.com, www.yahoo.com, www.msn.com,
www.bing.com, etc.
Website
A website is a collection of related
webpages with a common web
address. You get information on a
set of webpages about a particular
subject published by persons or
organizations. It contains pictures,
sound, videos, and other information.
ISP
The Internet Service Provider (ISP) is company or organization that provides
internet facility to users. Internet can be connected using Integrated Service
Digital Network (ISDN), leased line, cable line, and satellite connection. Some
popular ISP's of Nepal are: Nepal Telecom (NTC), Ncell, Mercantile Office System
(MOS), Web Suffer, SubisuCablenet, etc.
vedanta Let's Log in (A course in Computer Science) Book 5 40
Browsing
Browsing is the process of loading webpages of website on web browser. It just
means looking at different webpages using a browser. To see the contents of
website, we need to load webpages of websites on web browser.
Main Points to Remember
Internet is the network of computers spread all over the world.
Internet helps in many areas such as shopping, education,
communication, and entertainment.
The World Wide Web is one of the most popular services on internet.
There are many ‘chat rooms’ on the web that can be accessed to meet
new people, make new friends, stay in touch with old friends.
A website is a collection of one or more webpages.
In order to view website, you must open web browser where you enter
the URL of the website.
The first web page that appears on your browser is called the home
page.
E-mail is a service available on the internet that allows to exchange
messages with other internet users.
41 vedanta Let's Log in (A course in Computer Science) Book 5
EXERCISE
1. Write ‘T’ for true and ‘F’ for false statements.
a) The connection between two or more computers is called network.
b) Internet is known as network of networks.
c) Online Chat is the system of sending and receiving electronic message
or pictures.
d) A website is an internet computer that delivers webpages.
e) Web browser is a software or program that accesses webpages
f) Search engine is not a website.
g) URL specifies internet address of a file stored in server computer.
2. Fill in the blanks with correct words.
a)………………is the largest network of computers in the world.
b)Internet was firstly known as ………………………..
c)……………….is one of the fastest means of sending and receiving
messages.
d)……………… is the cheapest communication system.
e)…………….. allows the people to communicate with each other in
real time.
f) The main page of a website is known as …………………
g)……………………… is a search engine.
h)The …………… is company that provides internet facility to the users.
i) Each website has one main page called the …………………
3. Write the full forms of the following:
a) ISP b) ARPANET c) DOD d) URL
e) ISDN f) MOS g) NTC
vedanta Let's Log in (A course in Computer Science) Book 5 42
4. Match the following.
Group 'A' Group 'B'
i) Internet a) Introduced ARPANET
ii) ISP b) loading websites
iii) Search Engine c) largest computer network
iv) Web server d) buying and selling goods through Internet
v) Browsing e) website to search information
vi) Online shopping f) provides Internet access
vii) DOD g) powerful Internet computer
viii) Email h) stands for the Electronic mail
5. Answer the following questions.
a) What is internet?
b) Write a short note on “History of Internet”.
c) Write any four uses of internet.
d) What is e-mail? What are benefits of communicating through e-mail?
e) Write any two advantages of email as compared to postal service mail.
f) What is webpage?
g) What is web browser? Name some popular web browsers.
6. Explain the following terms:
i. URL ii. Online Shopping iii. ISP
iv.Search Engine v. Web Browser
Activities
a. With the help of your teacher, create an email account for yourself.
You can make an email account in Google. After making an email
account, send a mail to your friend/teacher.
43 vedanta Let's Log in (A course in Computer Science) Book 5
Lesson More on MS-Word
6
Word Processing
The process of writing, editing, and production of
documents, letters, and books using a special type of
computer program is called Word Processing.
Word Processor
The special type of computer program used for word
processing is called Word Processor. Some popular
examples of Word Processor are Microsoft Word,
Google Docs, Libre Office Writer, etc.
MS-Word
MS (Microsoft) - Word is a popular Word Processor developed by Microsoft
Corporation. It was first released in 1983 AD. MS-Word has useful features and
tools introduced to produce professionally created documents.
Features of MS-word
• We can prepare letters, notices, exam questions, project work reports,
books, newsletters, etc.
• We can edit the text.
• We can insert pictures, charts, etc.
• We can apply page border and color.
• We can format paragraphs with different alignment, line spacing, and
paragraph spacing.
vedanta Let's Log in (A course in Computer Science) Book 5 44
How to Open MS-Word
Step 1: On Windows desktop, click on the Search Windows icon.
Step 2: Find the Windows Search Box.
Step 3: In the search box, type word.
Step 4: Click on the Word 2016 (or other version) option in the search results.
Alternative method to run MS-Word
Step 1: Press Windows Key and R at the same time.
Run window appears.
Step 2: Type ‘winword’ as shown in the figure alongside.
Step 3: Finally click on OK button
45 vedanta Let's Log in (A course in Computer Science) Book 5
As you are already familiar with the different parts of MS-Word Window
in previous class, try to label the following MS-Word Windows.
Microsoft Word Screen 2016 /fvg]
Some important parts of MS Word Screen
Title Bar: It is on the top of the screen. It displays the name of your document.
File Menu: It is on the top left side of the screen. On clicking this button, you
can use several commands such as New, Open, Save, Print, etc.
Ribbon: It is found just below the title bar. It has several tabs such as Home,
Insert, etc.
Home Tab: It contains several groups such as Font, Paragraph, etc.
Working area: It is the place where you type, edit, and format your text.
Highlighting Text
You can highlight the desired text of your document by placing a colored
transparent rectangle over it.
vedanta Let's Log in (A course in Computer Science) Book 5 46
Step 1: From the Font group on Home tab, click the Text Highlight Color drop-
down arrow. Text Highlight Color
Step 2: Select the desired highlight color.
Step 3: Select the desired text you want to highlight.
Superscript
Superscript and Subscript
Superscript: It reduces the size of the selected text and
raises above the normal line.
Subscript
Example: 12th Bhadra. Here, 'th' after the number 12 is
a superscript.
Subscript: It reduces the size of the selected text and
lowers below the normal line.
Example: H20. Here, the digit '2' is a subscript.
Step 1: Select the required text. Keyboard shortcuts:
Step 2: From the Font group on Home tab, click SSuupbsecrrsicprtip–tC–tCrlt+rl=+ +
on Superscript or Subscript button as Underline – Ctrl + U
shown in the picture.
47 vedanta Let's Log in (A course in Computer Science) Book 5
2. Click the Subscript 1. Select the required text
button
Format Painter
This command is used to copy the format (not text), which you have already
applied to another text. Keyboard shortcuts:
Step 1: Select the text whose format you want to copy. Copy Format – Shift + Ctrl + C
Paste Format – Shift + Ctrl + V
Step 2: From the Clipboard group on Home tab, click Format Painter. The mouse
pointer changes to the Format Painter icon.
Step 3: Select the desired text on which you want to apply the copied format.
Note: Press Esc key or again click on Format Painter button to exit.
2 1 Select text
Click on Format Painter
Laxmi Prasad Devkota (12 November 1909- 14
September 1959) was a Nepali poet. Honoured
with the title of Maha Kavi in Nepali literature,
he is known as the poet with the golden heart.
Bhanubhakta Acharya
Laxmi Prasad Devkota (12 November 1909- 14
September 1959) was a Nepali poet. Honoured
with the title of Maha Kavi in Nepali literature,
he is known as the poet with the golden heart.
3
vedanta Let's Log in (A course in Computer Science) Book 5 48
Grow/Shrink Font
Grow Font command increases the size of font by one point and Shrink Font
command decreases the size of font by one point.
Step 1: Select the desired text. Grow Font Shrink Font
Step 2: From the Font Group on Home Tab,click on Grow Font or Shrink Font
as required.
Paragraph Formatting
Paragraph formatting is a process of making a paragraph attractive and more
readable. MS-Word provides different paragraph formatting tools such as
alignment, line spacing, indentation, etc.
Paragraph Alignment Keyboard shortcuts:
Alignment means adjusting the text with the
edges of paragraph. We can align the text either Left Align – Ctrl + L
Right Align - Ctrl + R
before or after typing it. Center Align – Ctrl + E
Justify – Ctrl + J
Paragraph Alignment Options:
Align Left: It aligns the selected paragraph to the left side of page.
Align Right: It aligns the selected paragraph to the right side of page.
Step 1: Select the paragraph that you want to align.
Step 2: On Home tab, in the Paragraph group, click on Align Left or
Align Right .
Align Center: It aligns the selected paragraph in the middle of the page.
Step 1: Select the paragraph that you want to center.
Step 2: On Home tab, in the Paragraph group, click on Center .
Justify: It aligns the selected paragraph with equal edges on both sides of
the page.
Step 1: Select the paragraph you want to justify.
Step 2: On Home tab, in the Paragraph group, click on Justify .
49 vedanta Let's Log in (A course in Computer Science) Book 5
Bhanubhakta Acharya is a Nepali poet and Bhanubhakta Acharya is a Nepali poet and
writer who translated the great epic the writer who translated the great epic the
Ramayana from Sanskrit to Khas language.
Born in 1814 A.D. in Chundi Ramgha, Tanahun Ramayana from Sanskrit to Khas language.
District, he was educated at home with a Born in 1814 A.D. in Chundi Ramgha, Tanahun
strong leaning towards religion from his
grandfather. District, he was educated at home with a
strong leaning towards religion from his
Align Left (Ctrl + L)
grandfather.
Align Right (Ctrl + R)
Bhanubhakta Acharya is a Nepali poet and Bhanubhakta Acharya is a Nepali poet and
writer who translated the great epic the writer who translated the great epic the
Ramayana from Sanskrit to Khas language. Ramayana from Sanskrit to Khas language.
Born in 1814 A.D. in Chundi Ramgha, Tanahun Born in 1814 A.D. in Chundi Ramgha, Tanahun
District, he was educated at home with a District, he was educated at home with a strong
strong leaning towards religion from his leaning towards religion from his grandfather.
grandfather. Justify (Ctrl + J)
Center (Ctrl + E)
Line spacing
Line spacing is the process of adjusting space between the lines of same
paragraph.
Step 1: Select the required paragraph or place the cursor in the
paragraph.
Step 2: In the Paragraph group, click the Dialog Box Launcher, paragraph
dialog box appears.
Step 3: Select the Line Spacing drop-down menu to set the desired line
spacing option.
Step 4: Click on OK.
Parijat is a Nepali writer. Her real name is Bishnu Parijat is a Nepali writer. Her real name is Bishnu
Kumari Waiba (Waiba is a subgroup of Tamang) Kumari Waiba (Waiba is a subgroup of Tamang)
but she wrote under the pen name paraijat but she wrote under the pen name paraijat (Parijat
(Parijat is a night-flowering fragrant jasmine is a night-flowering fragrant jasmine flower
flower). Her most acclaimed publication is Shiris
Ko Phool (The Blue Mimosa), which was adopted Line Spacing (Double)
as text in the University of Maryland, USA.
Line Spacing (Single)
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