basic of computer and information technology tools & network basics

IICS GTB Nagar (Prepared by : Ritika Pangasa)
NFORMATION
ECHNOLOGY OOLS
& ETWORK ASICS
1

COMPUTER
The computer is an electronic device that takes input from the user and
processes these data under the control of a set of instructions (called program)
and gives the result (output) and saves future use. It can process both
numerical and non-numerical (arithmetic and logical) calculations.
The word “Computer” comes from the word “compute” which means to
calculate. Computer can not do anything without a Program.
It represents the decimal numbers through a string of binary digits.
Charles Babbage is called the “Father of computer”. The First mechanical
computer designed by Charles Babbage was called Analytical Engine.
2

C Common
O Operating
M Machine
P Particularly
U Used for
T Technology, Trade
E Education, Experiment
R Research
3

IICS GTB Nagar (Prepared by : Ritika Pangasa) 4

Speed:
A computer works so fast that it can process any task and provide the output in
fractions of seconds. A powerful computer can handle trillions of instructions per
second. The speed of a computer is measured in microseconds and nanoseconds.
Accuracy:
The computers can work consistently with accuracy. The degree of accuracy in
computers is very high, they can perform calculations at almost 100% accuracy.
Errors may occur in a computer system but only because of wrong human input or
inaccurate data.
Diligence:
A computer doesn’t get tired or lacks of concentration. It can work for hours without
any fault. A computer can perform all the millions of calculations with the same
accuracy.
5

Versatility:
The computer has the ability to perform completely different kinds of works with the
same accuracy and efficiency at the same time.
Reliability:
The results obtained by the computer are very reliable. But this is true only when
the data given to the computer is correct and reliable.
Consistency:
It provides consistent results for the same set of data, i.e., if it given the same set of
data multiple times, then it will give the same result each time. One can use a
computer 24 hours a day or 365 days a year continuously.
Memory:
A computer has a built-in memory where it can store instant data immediately. The
primary memory (RAM) is used to store the data as long as the computer is
connected to the power source.
6

Storage Capacity:
Computer can store vast amount of data. To increase the storage of data, external
storage devices are used like external hard drives, pen drives. These devices can
be kept separate from the computer. One can also use cloud storage for this.
Remembrance Power:
The computer has the power to store any data or information for as long as we like.
It is our choice to decide how much data we want to store on the computer and
when to recall or erase that data.
Automation:
Computer can also be used to automate routine tasks with the help of a task
scheduler such as scanning for viruses, launching a specific application software or
many other maintenance tasks.
7

Evolution of Computers
Computers work through an interaction of hardware and software. There are five
apparent generations of computers.
Each generation is defined by a technological development that changes
necessarily how computers operate – leading to more compressed, inexpensive,
but more dynamic, efficient and growing machines.
1. First Generation Vacuum Tubes 1940 – 1956
2. Second Generation Transistors 1956 – 1963
3. Third Generation Integrated Circuits 1964 – 1971
4. Fourth Generation Microprocessors 1972 – 2010
5. Fifth Generation Artificial Intelligence 2010 – Onwards
8

Applications of Computers in Today’s world
Computers have become an essential part of modern human life. Since the
invention of computer they have evolved in terms of increased computing power
and decreased size.
Life in today’s world would be unimaginable without computers. They have made
human lives better and happier. There are many computer uses in different fields of
work.
Engineers, architects, jewelers, and filmmakers all use computers to design things.
Teachers, writers, and most office workers use computers for research, word
processing and emailing. Small businesses can use computers as a point of sale
and for general record keeping.
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1. Education
2. Health and Medicine
3. Communication
4. Financial Institutions
5. Business and Corporate Life
6. E-commerce
7. Defense
8. Entertainment
9. Graphics and Publication
10. Weather Forecasting
10

Education:
People can get different educational materials (such as images, videos, e-books,
etc.) in one place. All such information can be accessed through the Internet.
These are best suited for online classes, online tutoring, online examinations, and
creating assignments and projects. Distance learning is made productive and
effective through internet and video-based classes.
Health and Medicine:
Major uses of computers in medicine include hospital information system, data
analysis in medicine, medical imaging laboratory computing, computer assisted
medical decision making, care of critically ill patients, computer assisted therapy
and so on. ECG’s, radiotherapy wasn’t possible without computers.
11

Communication:
Modern computers come with a built-in webcam and microphone to make use of
communication easier. 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.
Financial Institutions:
Computers are being used by the financial institutions like banks for different
purposes. The foremost important thing is to store information about different
account holders in a database to be available at any time. Keeping the records of
the cash flow, giving the information regarding your account, etc. Nowadays online
banking system is being used 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.
12

Business and Corporate Life:
Every single information shared can be recorded by using computer. Official deals
and the issues were made even through online. We use email system to exchange
the information. It has wide uses in marketing, stock exchanges and bank.
E-commerce:
E-commerce (electronic commerce) describes the buying, selling, and exchanging
of products, services, and information via computer network. There are many
applications of e-commerce such as banking, shopping in electronic malls, buying
stocks, finding a job, conducting an auction, collaborating electronically with
business partners around the globe, marketing & advertising and providing
customer service.
13

Defense:
Computers are the main tools which help in developing missiles and other
equipment in the defense system. It builds the links between the soldiers and
commanders through the satellite. Construction of weapons and controlling their
function is not possible without the aid of computers. The list of the criminals and
the records of the cops are maintained regularly in the system.
Entertainment:
The use of computers in the entertainment field like movies, music, presentations,
sports and games has increased over the last decade. They are used to edit
movies, create full length cartoon movies, multimedia presentations etc. The user
can download and view movies, play games, chat, book tickets for cinema halls,
use multimedia for making movies, incorporate visual and sound effects using
computers, etc.
14

Graphics and Publication:
Computer is a powerful advertising media. Advertisement can be displayed on
different websites, electronic-mails can be sent and reviews of a product by
different customers can be posted. These are also used to create an advertisement
using the visual and the sound effects.
Weather Forecasting:
Weather forecasting is never easy for humans because it depends on many factors
that are continually changing. 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.
15

Types of Computer
On the basis of data handling capabilities, the computer is of three types:
1. Digital Computer
2. Analog Computer
3. Hybrid Computer
COMPUTER
ANALOG DIGITAL
MICRO MINI MAINFRAME SUPER
HYBRID
16

Digital Computer
• Digital computers are used to easily perform calculations and logical operations
at high speed.
• It takes raw data as an input and processes it with programs stored in its
memory to produce the final output.
• It only understands the binary input 0 and 1, so the raw input data is converted
to 0 and 1 by the computer and then it is processed by the computer to produce
the result or final output.
• These allow users to store a large amount of information.
• New features can easily be added to the digital systems and it also provides the
ability to change the program without making any changes in the hardware of the
system.
• All modern computers, like laptops, desktops including smartphones are digital
computers.
17

Analog Computer
• An analog computer is particularly designed to process analog data.
• It is used where we don’t need exact values or need approximate values such as
speed, temperature, pressure etc.
• These computers allow real-time computation and operations at the same time.
• It can directly accept the data from the measuring device without first converting
it into numbers and codes.
• It measures the continuous changes in physical quantity.
• It gives output as a reading on a dial or scale.
• For example speedometer, mercury thermometer, etc.
18

Hybrid Computer
• Hybrid computers are devices that have features of both digital and analog
computers.
• These devices are similar in speed to analog computers and are identical to
digital computers in their memory and accuracy.
• It accepts analogue signals and convert them into digital form before processing.
• These computers help in online data processing.
• For example ECG machine, gasoline station, ultrasound machine, etc.
19

Micro Computer
• A microcomputer is a small, relatively inexpensive computer with a
microprocessor as its central processing unit.
• It is designed for use by one person at a time.
• It uses a single integrated semiconductor chip for its central processing unit
(CPU).
• They also contain memory in the form of read-only memory (ROM) and random
access memory (RAM), input/output (I/O) ports, and a bus or system of
interconnecting wires, all housed in a single unit usually referred to as a
motherboard.
• These are generally known as PCs (personal computers).
• Common micro computers are laptops, desktops, mobile phones, notebooks,
etc.
20

Mini Computer
• Minicomputers may contain one or more processors, support multiprocessing
and tasking, and are generally flexible enough to high workloads.
• It generally supports multiple users at a time.
• They are smaller than mainframe or supercomputers, minicomputers are more
powerful than personal computers and workstations.
• These are mainly used as small or mid-range servers operating business and
scientific applications.
• It is designed for business applications and services, and also can do time-
sharing, batch processing, online processing, etc.
21

Mainframe Computer
• A mainframe computer is a combination of memory (RAM) and many
processors. It acts as a central processing unit for many workstations and
terminals connected with it.
• It is an expensive computer which used to process the large and huge amount of
data.
• It does an important role in e-business where hundreds to thousands of people
connect to a server to precede their request in a real time.
• It deals with thousands of users to execute their instructions
simultaneously. They can support multiple programs at the same time.
22

Super Computer
• A supercomputer is the fastest, largest and most expensive computer that can
process a significant amount of data very quickly.
• These machines are capable of handling the massive amount of calculations
that are beyond the human capabilities, i.e., the human is unable to solve such
extensive calculations.
• They can support more than a hundred users at a time.
• The applications of supercomputers include weather forecasting, exploring
universe, understanding earthquakes, life science research, testing nuclear
weapons, etc.
23

Components of computer
All types of computers follow a same basic logical structure and perform the
following five basic operations for converting raw input data into information useful
to their users.
Take Input The process of entering data and instructions into the computer system
Store Data
Saving data and instructions so that they are available for processing as and when
required.
Processing
Data
Performing arithmetic, and logical operations on data in order to convert them into
useful information
Output
Information
The process of producing useful information or results for the user, such as a printed
report or visual display
Control the
workflow
Directs the manner and sequence in which all of the above operations are performed
24

CPU
25

Input Unit
• This unit contains devices with the help of which we enter data into computer.
• This unit makes link between user and computer.
• The input devices translate the information into the form understandable by
computer.
CPU (Central Processing Unit)
• CPU is considered as the brain of the computer.
• It performs all types of data processing operations.
• It stores data, intermediate results and instructions (program).
• It controls the operation of all parts of computer.
It has following three components
• ALU (Arithmetical and Logical Unit)
• MU (Memory Unit)
• CU (Control Unit)
26

ALU (Arithmetical & Logical Unit)
• ALU and CU are the heart of the CPU.
• This unit performs all the arithmetic and logical operations such as addition,
subtraction, logical AND, OR etc.
CU (Control Unit)
• It decodes the instructions, and controls all the other internal components of the
CPU to make it work.
• It directs operation of the processor.
• It tells the computer’s memory, arithmetic/logic unit and input and output devices
how to respond to a program’s instructions.
MU (Memory Unit)
• It stores all the data and the instructions required for processing, intermediate
results of processing, final results of processing.
• All inputs and outputs are transmitted through the main memory.
• It is also known as internal storage unit or the main memory or the primary
storage or Random Access Memory (RAM).
27

Output Unit
• This unit consists of devices with the help of which we get the information from
computer.
• This unit is a link between computer and users.
• The output devices translate the computer’s output into the form understandable
by users.
28

Input Devices
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.
• Various input devices are:
• Keyboard
• Mouse
• Joy Stick
• Light pen
• Scanner
• Biometric Device
• Magnetic Ink Card Reader (MICR)
• Optical Character Reader (OCR)
• Bar Code Reader (BCR)
• Optical Mark Reader (OMR)
• Digital Camera
• Webcam
• Microphone
• Touchpad
29

Keyboard
It is one of the primary input devices used to input data and commands. It has
function keys, control keys, arrow keys, keypad and the keyboard itself with the
letters, numbers and commands. These are connected to the computer through
USB or Bluetooth. A laptop keyboard is more compact than a desktop keyboard to
make the laptop smaller and lighter. Smartphones and tablets use on-screen
keyboard to input messages and select commands.
Types of Keys
• Numeric Keys: It is used to enter numeric data or move the cursor. It usually consists
of a set of 17 keys.
• Typing Keys: The letter keys (A-Z) and number keys (0-9) are among these keys.
• Control Keys: These keys control the pointer and the screen. There are four directional
arrow keys on it. Home, End, Insert, Alternate(Alt), Delete, Control(Ctrl), etc., and
Escape are all control keys (Esc).
• Special Keys: Enter, Shift, Caps Lock, Num Lock, Scroll Lock, Tab, etc., and Print
Screen are among the special function keys on the keyboard.
• Function Keys: The 12 keys from F1 to F12 on the topmost row of the keyboard.
30

Mouse
The mouse, sometimes called a pointer, is a hand-operated input device used to
manipulate objects on a computer screen. The standard mouse has two buttons
toward the front (to left-click and right-click) and a scroll wheel in the center (to
quickly move the screen up and down).
Whether the mouse uses a laser or ball, or is wired or wireless, a movement
detected from the mouse sends instructions to the computer to move the cursor on
the screen in order to interact with files, windows, and other software elements.
Main functions of mouse:
• Move the mouse pointer
• Selection (generally by using left click once)
• Open or execute a program (generally by using left click twice)
• Opening the pop-up menu (generally by using right click once)
• Drag-and-drop
• Hovering
• Scroll Up & Down 31

Joystick
A joystick is also a pointing input device like a
mouse. It is made up of a stick with a spherical
base. The base is fitted in a socket that allows
free movement of the stick. The movement of
stick controls the cursor or pointer on the
screen. It is actually used in computers for
playing games .
32

Light Pen
Light Pen, which is similar to the Normal Pen,
is a pointing input device that is used to select
the menu or picture display on the screen of a
mobile or computer. It may be used to direct
viewers' attention to a specific area, such as a
picture or text in a presentation.
33

Scanner
A scanner is an electronic device that can
scan handwritten or printed documents and
pictures and transforms them into a digital file
format. It uses the pictures and pages or text
as input. This is then converted by the scanner
into a digital file (soft copy) and stored in
electronic form on a computer or mobile
device. It basically coverts the hard copy of
data to soft copy.
34

Bio-metric Device
Biometrics refers to a process in which
a person is identified through his or her
biological features such as fingerprints,
eye cornea, face structure, etc.
A biometric device is a security
identification and authentication device.
Voice and fingerprint recognition are
also both common forms of biometric
scanning.
35

MICR
(Magnetic Ink Character Reader)
MICR is an input device which is
designed to read the text printed with
magnetic ink. It is widely used in banks
to process the cheques and other
organizations where security is major
concern. It can process three hundred
cheques in a minute with accuracy. The
details on the bottom of the cheque
(MICR No.) are written with magnetic
ink.
36

OCR
(Optical Character Reader)
OCR computer input device is designed
to convert the scanned images of
handwritten, typed or printed text into
digital text. It is widely used to convert
hard copy legal or historic documents
into PDFs, electronic files.
It processes and copies the physical
form of a document using a scanner.
The converted documents can be edited
if required like we edit documents
created in MS Word.
37

BCR
(Bar Code Reader)
A BCR (barcode reader or scanner), also
known as a POS (point of sale)
scanner is a hardware input device
capable of reading a barcode using
a laser. It can load the details of the
product or log information about that
product into a database.
Today, many smartphones with the
proper apps are also capable of
scanning and reading barcodes.
38

OMR
(Optical Mark Recognition)
OMR is a device capable of capturing human
marked documents such as surveys and
tests to a digital format. For a document to
be read by the device it needs to be in a
specified background.
This technology is used if data is to be
collected from a large number of sources
simultaneously, a large volume of data must
be collected and processed in a short period
of time. The information is gathered by
answers to multiple- choice questions. It
allows for the processing of hundreds or
thousands of documents per hour.
39

Digital Camera
It is a digital device as it captures images
and records videos digitally and then stores
them on a memory card.
A digital camera is also known as a digicam.
With smartphones evolving to include near
professional-grade camera capabilities, the
popularity of digital cameras is decreasing.
Smartphones offer more convenience,
portability, easier photo sharing abilities, and
a cheaper price.
40

Webcam
Any camera which is connected to a
computer is called a webcam. The in-built
camera provided on a computer can also be
considered a webcam. It is an input device
as it can take pictures, and can be used to
record videos if required. The pictures and
videos are stored in the computer memory
and can be displayed on the screen if
required. It is built in the laptops and are
usually used in video calls.
41

Microphone
The Microphone is a computer input device
that is used to input the sound. It receives
the sound vibrations and converts them into
audio signals or sends to a recording
medium. The audio signals are converted
into digital data and stored in the computer.
42

Touchpad
It is usually found in laptops as a
substitute for the mouse. It allows you to
move or control the cursor on the screen
using your finger. Just like a mouse, it also
has two buttons for right and left click.
Using the touchpad, you can perform all
the tasks that you do with a mouse, such
as selecting an object on the screen, copy,
paste, delete, open a file or folder, and
more.
43

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.
• Various output devices are:
• Monitor
• Monochrome
• CRT
• Flat Panel (LCD, LED, Plasma)
• Printer
• Impact Printer (Dot Matrix, Daisy Wheel, Drum, Chain)
• Non-Impact Printer (Inkjet, Laser)
• Projector
• Plotter
• Speakers, Headphones
44

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. It is also known as a visual display unit (VDU).
Terms related to monitor
• Resolution: It describes the visual dimensions of any given display which is expressed
in terms of width and height. For example full HD 1080p resolution has a resolution of
1920 x 1080 pixels.
• Pixels (Picture Element): These are the smallest physical points on a display. Pixels
and resolution are directly correlated and a higher resolution equals a higher number of
pixels on a monitor screen.
• DPI / PPI: DPI (dots per inch / pixels per inch) is the number of dots found within a one-
inch line of a scan or print. It is a description of a monitor screen’s pixel density.
• Refresh Rate: It is the number of times the entire screen can be updated per second
which is measured in Hz (hertz).
45

Types of monitor
Monochrome monitors CRT monitors (Cathode Ray Tube)
(single color display monitor mainly black and white)
LCD monitors
(Liquid Crystal Display)
LED monitors
(Light Emitting Diode)
Plasma monitors
46

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.
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.
47

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.
Impact printer uses a hammer or print
head to print the character or images
onto the paper. The hammer or print
head strikes or presses an ink ribbon
against the paper to print characters
and images.
Non-impact printers don't print
characters or images by striking a print
head or hammer on the ink ribbon
placed against the paper. These printers
can print a complete page at a time, so
they are also known as page printers.
48

Plotter
A plotter is a kind of printer for computers which are used to print to paper which is
very large in size. It can print on a wide variety of flat materials including plywood,
aluminum, sheet steel, cardboard, and plastic. It can be used to draw charts,
architectural blueprints, textile printing, banners and billboards, geographical
layouts, building plans, etc.
49

Speakers / Headphones
Speaker is an output device which allow to listen to
voice like music and conversation with people. They
receive audio input from the computer’s sound card
and produce audio output in the form of sound waves.
The amplitude and frequency define the sound
produced by speakers. The frequency determines the
pitch of the sound of how high or low it is. The air
pressure created by the speakers' sound waves
determines the loudness or amplitude.
Headphone is an output device that can be plugged
into a computer, laptop, smartphone, mp3 player or
other device to privately listen to audio without
disturbing anyone around. These are plug-and-play
devices and do not require any type of installation
before use.
50

Memory
In computer system, there is a special unit named as memory unit which deals with
the storage of all input, processing results (intermediate results) and the output
data. Everything in computer is stored in the computer memory which is basically
of two types namely:
• Primary memory (Main memory or Internal memory)
• Secondary memory (Auxiliary memory or External memory)
The storage units in every memory device is in the form of bit, byte, etc. The
storage units in hierarchy are:
Bit (Binary digit i.e. 0, 1)
1 Nibble = 4 Bits
1 Byte = 8 bits = 2 Nibbles
1 KB (Kilobyte) = 1024 Bytes
1 MB (Megabyte) = 1024 KB
1 GB (Gigabyte) = 1024 MB
1 TB (Terabyte) = 1024 GB
1 PB (Petabyte) = 1024 TB
1 EB (Exabyte) = 1024 PB
1 ZB (Zettabyte) = 1024 EB
1 YB (Yottabyte) = 1024 ZB
51

Primary Memory
In computer system, the primary memory or main memory is the memory which is
directly connected to the motherboard (the largest electronic printed circuit board in
the computer system). Whenever any data is processed, the processor firstly looks
for it in the primary memory.
The primary memory is of 3 types:
• RAM (Random Access memory)
• ROM (Read Only memory)
• Cache
HARD
DISK
PROCESSOR
CACHE
RAM
52

RAM (Random Access Memory)
It is the main memory which stores the currently used data and instructions. It is
volatile in nature means, whenever the computer system restarts it refreshes the
data which is stored in RAM. To increase the speed of computer system, the RAM
storage is increased.
It is basically of two types: Static and
Dynamic. In static RAM, it retains the contents
till the shutdown of the computer system.
Whenever the computer system is shut down
and restarts and whenever the memory is full,
the contents of static RAM are refreshed.
While in dynamic RAM, the contents are
refreshed after every nanoseconds.
53

ROM (Read Only Memory)
It is the main memory which stores the booting instructions of the computer
system. When the computer starts, the initial instructions which it needs to follow
are stored in the Read Only Memory. It is non-volatile in nature.
It is basically of three types: PROM, EPROM,
EEPROM.
• PROM (Programmable ROM): In this ROM,
the data can’t be altered or change.
• EPROM (Erasable PROM): In this ROM, data
written can be altered using UV-rays (Ultra
Violet).
• EEPROM (Electrically EPROM): In this ROM,
data written can be altered or changed using
electric signals, waves. 54

Cache
It is the main memory which stores the currently and frequently used data and
instructions. It is the built in memory of the processor. Whenever processor needs
something, it firstly looks for it in the cache memory that it is there or not. If it is
there, then it will take it and if it is not there, then the cache memory asks for that in
the RAM. The cache memory is the fastest and smallest memory of the computer
system.
55

Secondary Memory
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.
The secondary memory is of following types:
• Hard disk (Hard drive or HD or HDD)
• Optical disc
• Floppy disc
• SD card
• Pen drive
• Magnetic tape
56

Hard Disk (Hard Drive or HD or HDD)
It is a magnetic disc that stores data permanently, as it is a non-volatile storage
device. 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.
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.
57

Optical Disc
It is a portable, computer storage disk that stores data digitally and uses laser
beams to read and write data. It uses the optical technology in which laser light is
centered to the spinning disks.
There are three main types of optical media:
• CD (Compact Disc)
• DVD (Digital Versatile Disc / Digital Video Disc)
• BD (Blu-ray disc)
58

Computers can read and write to CDs and DVDs using a CD writer or DVD writer
drive, and a Blu-ray is read with a Blu-ray drive. CDs can store up to 700 MB of
data, and DVDs can store from 4.7 GB to 8.4 GB of data. Blu-ray discs, which are
the newest type of optical media, can store from 25 GB to 50 GB of data.
Various formats of CDs available are:
CD-ROM : It is a read-only disc. These types of disks are created commercially and
you cannot save data to them once they have been created.
CD-R : It is a Write Once Read Multiple (WORM) disc. These discs can only record
data once and then the data becomes permanent on the disc. After writing to a CD-
R, it becomes a CD-ROM.
CD-RW : It is an erasable disc that can be reused. The data on a CD-RW disc can
be erased and recorded over numerous times.
59

Floppy Disc
A floppy disk is a magnetic storage
medium for computer systems. The
floppy disk is composed of a thin, flexible
magnetic disk sealed in a square plastic
carrier. In order to read and write data
from a floppy disk, a computer system
must have a floppy disk drive (FDD).
Types of floppy disc:
Size
(in inches)
Storage
(in MB)
3.5 1.44
5.25 1.2
8 1
60

SD Card (Secure Digital Card)
It is most often used in portable and
mobile devices such as smartphones
and digital cameras. One can remove it
from the device and see the things
stored in it using a computer with a card
reader.
Pen Drive
Pen drive is a compact secondary storage device. It
connects to a computer via a USB (Universal Serial
Bus) port. It is commonly used to store and transfer
data between computers. It is a PnP (Plug and Play)
device. One can also store the important documents
and pictures, music, videos in the pen drive and keep it
at a safe place. 61

Relation between Hardware and Software
Hardware and software are mutually dependent on each other. Both of them must
work together to make a computer produce a useful output. To get a particular job
done on the computer, relevant software should be loaded into the hardware. A
software acts as an interface between the user and the hardware.
• Software cannot be utilized without supporting hardware likewise hardware
(without set of programs to operate upon) cannot be utilized and is useless.
• Hardware is a one-time expense whereas software development is very
expensive and is a continuing expense.
• Different software applications can be loaded on a hardware to run different jobs.
• If hardware is the 'heart' of a computer system, then software is its 'soul'. Both
are complementary to each other.
62

Software
Software is a set of instructions which are used to accomplish a particular task.
These basically build a communication to the hardware devices. Each and every
task in computer system is carried out by a particular software.
• Software's are categorized as:
• System Software
• Operating System
• Language Processor (Language Translator)
• Device Driver
• Application Software
• General Purpose Application
• Customized Application
• Utility Software
63

System Software
These are those software’s which directly interact
with the hardware devices and which are
necessary for the computer system to work.
These are the first software’s to work when the
computer system starts and work till the
shutdown process.
Application Software
These are those software’s which are used to
carry out a specific task like creating a poster,
resume, etc. These software’s basically
increases the task of the computer that it can
perform as per the user’s requirements.
User
Application
Software
System
Software
Hardware
64

System Software Vs Application Software
System Software Application Software
System Software maintain the system
resources and give the path for application
software to run.
Application software is built for specific
tasks.
Without system software, system can’t run. Without application software, computer
system can run.
It acts as an interface between the
Application Software and Computer
hardware.
It acts as an interface between the end-
user and System Software.
System software runs when system is
turned on and stop when system is turned
off.
Application software runs as per the user’s
request.
Low level languages are used to write the
system software.
High level languages are used to write the
application software.
Examples are Unix, MS-Windows, etc. Examples are Photoshop, MS-Office, etc.
65

Types of System Software
Operating System: These are the software’s which gives the platform for other
software’s to work effectively, efficiently. It bridges up the communication between
the application software’s and the hardware. These manages the entire working of
the computer system i.e. the input output devices, memory devices, processes, etc.
Language Processors: These are the language translators which converts the
high level language, assembly language data to machine language that the
computer can understand and process.
Device driver: These are the software’s which tells that how a particular device will
communicate with the computer system. For example: printer driver, motherboard
driver, etc.
66

Types of Application Software
General Purpose Application: These are those software’s which are developed
by considering the requirements of the particular group of users. For example, MS-
Office for office users; Corel Draw, Photoshop for graphic designers; Tally, Busy for
accountants; etc.
Customized Application Software: These are those software’s which are
developed on demand of a particular person, group, organization and it includes all
the features mentioned by only that particular user. For example, student
management software used by a particular school, etc.
Utility Software: These are those software’s which are used to enhance the
efficiency of the computer system. These increases the life of the computer system
by maintaining the hardware devices, cleaning up the unnecessary files, etc. For
example Antivirus software, Disk cleanup, etc.
67

Types of Language Processors (Language Translators)
Compiler: This is a language translator which translates the high level language to
the machine language whole program at a time. It checks for the syntax errors. For
example, Turbo compiler for C, C++ language; javac compiler for java language,
etc.
Interpreter: This is a language translator which translates the high level language
to the machine language one line at a time. For example, java interpreter for java
language; python interpreter for python language, etc.
Assembler: This is a language translator which translates the assembly language
in machine language. Assembly language is the language which contains pseudo
codes / mnemonics for the computer to perform some tasks.
68

Operating System
An operating system acts as an intermediary between the user of a computer and
computer hardware. The purpose of an operating system is to provide an
environment in which a user can execute programs conveniently and efficiently.
An operating system is a software that manages the computer hardware.
Functions of OS:
1. Process management
2. Processor management
3. Memory management
4. Security management
5. Scheduling
6. Input - Output management
69

Basic types of Operating System
1. Single user: In this, only one user can work at a time.
Example: MS-DOS
2. Multi user: In this, more than one user can work at a time.
Example: MS-Windows, Linux, Unix
3. Single tasking: In this, only one task can be performed at a time.
Example: MS-DOS
4. Multi tasking: In this, more than one task can be performed simultaneously.
Example: MS-Windows, Linux, Unix
70

Types of Operating System
1. Batch Operating System:
The user of a batch operating system never directly interacts with the computer. In
this type of OS, every user prepares his or her job on an offline device and submit
it to the computer operator. Jobs are processed on a first-come, first-serve basis,
i.e., in the order of their submission without any human interference.
For example, bank statement, payroll statement, the credit card bill generated by
banks, etc.
2. Multitasking/Time Sharing OS
Time-sharing operating system enables people located at a different terminal
(shell) to use a single computer system at the same time. The processor time
(CPU) which is shared among multiple users is termed as time sharing.
For example: Unix, etc.
71

3. Multiprocessing OS
In Multiprocessing, Parallel computing is achieved. There are more than one
processor present in the system which can execute more than one process at the
same time. This will increase the throughput of the system.
For example: Unix, etc.
4. Real Time OS
A real time operating system time interval to process and respond to inputs is very
small. In Real Time systems, each job carries a certain deadline within which the
Job is supposed to be completed, otherwise the huge loss will be there or even if
the result is produced then it will be completely useless.
Examples: Military Software Systems, Space Software Systems, Air traffic
controller systems, robots are the Real time OS example.
72

5. Distributed OS
Distributed systems use many processors located in different machines to provide
very fast computation to its users. It uses multiple independent processors (CPUs)
to serve multiple users and multiple real-time applications.
For example: LOCUS, etc.
6. Network OS
Network Operating System runs on a server. It provides the capability to serve to
manage data, user, groups, security, application, and other networking functions.
These are the centralized servers and highly stable.
For example: Microsoft Windows Server 2003, Microsoft Windows Server 2008,
UNIX, Linux, Mac OS X, etc.
73

7. Mobile OS
Mobile operating systems are those OS which is especially that are designed to
power smartphones, tablets, and wearables devices.
For example: Android, iOS, Blackberry, etc.
74

Virus (Vital Information Resource Under Siege)
It is a self-replicating program which enters the computer system by attaching
itself to another computer program, and replicates itself across the system. It is a
type of malware (malicious software) which interferes in the overall working of the
computer system. It can infect other system software or resources, modify or
disable core functions or applications, and copy, delete or encrypt data.
A virus can be spread when a user opens an email attachment, runs an executable
file, visits an infected website or views an infected website advertisement, known
as malvertising. It can also be spread through infected removable storage devices
like USB device.
75

Symptoms of Virus
 The computer takes a long time to start up, and performance is slow.
 There will be double extension to files like .jpeg.vbs, etc.
 The computer experiences frequent crashes or shutdown and error messages.
 Not able to find your files or programs.
 New programs or desktop icons that are unknown to you and you didn’t
installed/created them.
 Programs running and closing without your consent.
 The amount of storage on the computer is reduced.
 Change in the name of your hard drive & also change in its volume.
 Changes in your security settings.
 Unusual emails/social media messages being sent without your permission.
 A virus may damage your hard drive and our device may freeze or crash as a result of
this. 76

Protection from Computer Virus
 Install current antivirus software and keep it up to date.
 Run daily scans of antivirus software.
 Keep Your Operating System Updated
 Disable autorun to prevent viruses from spreading to any media connected to the
system.
 Don't click on web links sent via email from unknown senders.
 Don't download files from the internet or email from unknown senders.
 Don't use Pirated software
77

Anti Virus
It is a software which basically detects, deletes and repairs the files affected by the
virus. Every virus is identified by a unique code known as its signature code and to
rectify the files, the anti-virus uses that code to remove that from the computer
system.
For example, Norton, Quick Heal, McAfee, Kaspersky, etc.
78

IPR (Intellectual Property Rights)
Intellectual property rights are the rights given to each and every person for the
creations of new things according to their minds. These are the legal rights that
cover the benefits given to individuals who are the owners and inventors of a work
and have created something unique with their intellectual creativity or capability.
Every person related to areas such as literature, music, invention, etc., can be
granted such rights, which can then be used in the business practices by them.
Intellectual property rights are at the foundation of the software industry.
There are 4 types which are relevant to software:
1. Patent
2. Copyright ©
3. Trade secret
4. Trademark ™ / ®
79

Patents
A patent gives its owner the right to exclude others from making, using, selling, and
importing an invention for a limited period of time. These are granted in exchange
for enabling public disclosure of the invention.
Copyrights ©
Copyright is a term that describes ownership of control of the rights to the use and
distribution of certain works of creative expression, including books, video, movies,
music and computer programs. It does not cover ideas and information
themselves, only the form or manner in which they are expressed.
80

Trade Secret
A trade secret is any formula, pattern, device, process, tool, or method (that is not
generally known to others) is maintained in secrecy by its owner, and gives its
owner a competitive advantage because it is kept secret.
Trademarks ™ / ®
A trademark is a graphical representation that is used to distinguish the goods and
services of one brand from those of others. It does not protect technology, but the
names or symbols used to distinguish a product in the marketplace. It may consist
of a letter, number, word, phrase, logo, graphic, shape, sound or combination of
these things.
81

File Extensions (Last name of the file which is used to identify the type of file)
1. .docx : MS Word 2007 onwards (for earlier versions, .doc is used)
2. .xlsx : MS Excel 2007 onwards (for earlier versions, .xls is used)
3. .xlsm : MS Excel 2007 onwards (Macro Enabled workbook)
4. .pptx : MS PowerPoint 2007 onwards (for earlier versions, .ppt is used)
5. .accdb : MS-Access 2007 onwards
6. .odt : Open document text file
7. .ods : Open document spreadsheet file
8. .odp : Open document presentation file
9. .odg : Open document graphics file
82

10. .pdf : Portable document folder
11. .jpg / .jpeg : Joint Photographic Experts Group
12. .png : Portable Network Graphics
13. .bmp : Bitmap Picture
14. .gif : Graphics Interchange format
15. .wav : wave sound
16. .amr : Recorded audio
17. .mp3 : Media Player 3
18. .avi : Audio Video Interleave
19. .midi / .mid : Musical instrument digital interface
83

20. .mp4 : Media Player 4
21. .mpeg : Moving Pictures Experts Group
22. .wmv : Window Media Video
23. .zip : Compressed file using Winzip
24. .rar : Compressed file using Winrar
25. .txt : Text file (Notepad)
26. .rtf : Rich text format (WordPad)
27. .bak : Windows Backup file
28. .exe : Executable file (Program files)
84

29. .html / .htm : HTML file (Hypertext Markup Language)
30. .cpp : C++ program file
31. .c : C program file
32. .py : Python Program file
33. .java : Java Program file
34. .php : PHP Program file (Perl Hypertext Preprocessor)
35. .js : JavaScript file
36. .css : CSS file (Cascading Style Sheet)
85

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