NCERT Textbook - Computer & its Components, Information & Computer Technology Class 10 | Information & Computer Technology (Class 10) - Notes & Video PDF Download

 Page 1


1
Computer and its Components
Chapter 1
Computer and its Components
Learning Objectives 
By the end of this chapter, learner will be able to:
•	 Lis t	 fiv e	 c omput er	 applic a tions	 which	 ar e	 used	 on	 the	 daily	 basis.
•	 Iden tif y	 the	 diff er en t	 Input	 /	 Output	 de vices.	
•	 Describe	 the	 pr ocess	 of	 changing	 da t a	 fr om	 input	 t o	 output	 (The	 IPO	 cy cle).
•	 Explain	 the	 c onnectivity	 of	 de vices	 thr ough	 diff er en t	 kinds	 of	 ports.	
•	 Diff er en tia t e	 be tw een	 primar y	 and	 sec ondar y	 memor y .
•	 St a t e	 the	 purpose	 of	 diff er en t	 softw ar es.
•	 T a b u l a t e 	 t h e 	 d i ff e r e n c e 	 b e t w e e n 	 d i ff e r e n t 	 t y p e s 	 o f 	 c o m p u t e r s 	 a c c o r d i n g 	 t o 	 t h e i r 	 s i z e 	 a n d	
pr ocessing	 c apabilities.
IntroduCtIon
The computer is just a dead collection of plastic, silicon and metal until you press the 
‘Power’ button. One little burst of electricity and it starts a string of events that puts life 
and power into the machine. But, even at this stage, the computer is unaware of the 
potential that it holds within itself. The computer, today, is a fundamental part of the 
information age. 
Initially, computers were developed to perform mathematical operations, but later on, they 
were used to store the result of those operations, which with the time leads to the storage 
of other data or information.
As we are talking about data and information, now we will learn what data is and what 
is called as information?
d ata is a collection of unprocessed facts, figures, and symbols.
e.g. Ram, age, 32, years, old
Page 2


1
Computer and its Components
Chapter 1
Computer and its Components
Learning Objectives 
By the end of this chapter, learner will be able to:
•	 Lis t	 fiv e	 c omput er	 applic a tions	 which	 ar e	 used	 on	 the	 daily	 basis.
•	 Iden tif y	 the	 diff er en t	 Input	 /	 Output	 de vices.	
•	 Describe	 the	 pr ocess	 of	 changing	 da t a	 fr om	 input	 t o	 output	 (The	 IPO	 cy cle).
•	 Explain	 the	 c onnectivity	 of	 de vices	 thr ough	 diff er en t	 kinds	 of	 ports.	
•	 Diff er en tia t e	 be tw een	 primar y	 and	 sec ondar y	 memor y .
•	 St a t e	 the	 purpose	 of	 diff er en t	 softw ar es.
•	 T a b u l a t e 	 t h e 	 d i ff e r e n c e 	 b e t w e e n 	 d i ff e r e n t 	 t y p e s 	 o f 	 c o m p u t e r s 	 a c c o r d i n g 	 t o 	 t h e i r 	 s i z e 	 a n d	
pr ocessing	 c apabilities.
IntroduCtIon
The computer is just a dead collection of plastic, silicon and metal until you press the 
‘Power’ button. One little burst of electricity and it starts a string of events that puts life 
and power into the machine. But, even at this stage, the computer is unaware of the 
potential that it holds within itself. The computer, today, is a fundamental part of the 
information age. 
Initially, computers were developed to perform mathematical operations, but later on, they 
were used to store the result of those operations, which with the time leads to the storage 
of other data or information.
As we are talking about data and information, now we will learn what data is and what 
is called as information?
d ata is a collection of unprocessed facts, figures, and symbols.
e.g. Ram, age, 32, years, old
2
Information and Computer Technology
information is a processed form of data. It is organized, meaningful, and useful.
e.g. Ram is 32 years old.    Or    Ram’s age is 32 years.
A computer can be defined as an advanced electronic device that takes raw data as input 
from the user. It uses a set of instructions (called program) to process the data and give 
the result (output). The result can be used immediately or saved for future use.
1. Hardware and Software
In the process of converting data to information, a computer uses hardware and software. 
At the simplest level, all computers consist of these two basic components; the hardware 
and the software. 
h ardware is any part of the computer that has a physical structure that can be seen and 
touched, though some may be so tiny that they are invisible to the naked eye. 
s oftware is the instruction set that tells the computer how to perform tasks. Software is 
intangible i.e., that cannot be seen and touched, but its effect is clearly defined.
Input devices, output devices, a system unit, storage devices, and communication devices 
are all components of computer hardware. 
1.1  Hardware components are classified into following categories
I. Input devices 
input devices are the devices that allow a user to enter data and instructions into a 
computer such as keyboard, mouse, microphone, scanner, trackball, joystick, graphics 
tablet and digital camera.
The various functions of input devices are:
 ? They accept data and instructions from the user.
 ? They convert these instructions and data from human readable form to machine 
readable form.
 ? They supply the converted instructions and data to the CPU for further  
processing.
Page 3


1
Computer and its Components
Chapter 1
Computer and its Components
Learning Objectives 
By the end of this chapter, learner will be able to:
•	 Lis t	 fiv e	 c omput er	 applic a tions	 which	 ar e	 used	 on	 the	 daily	 basis.
•	 Iden tif y	 the	 diff er en t	 Input	 /	 Output	 de vices.	
•	 Describe	 the	 pr ocess	 of	 changing	 da t a	 fr om	 input	 t o	 output	 (The	 IPO	 cy cle).
•	 Explain	 the	 c onnectivity	 of	 de vices	 thr ough	 diff er en t	 kinds	 of	 ports.	
•	 Diff er en tia t e	 be tw een	 primar y	 and	 sec ondar y	 memor y .
•	 St a t e	 the	 purpose	 of	 diff er en t	 softw ar es.
•	 T a b u l a t e 	 t h e 	 d i ff e r e n c e 	 b e t w e e n 	 d i ff e r e n t 	 t y p e s 	 o f 	 c o m p u t e r s 	 a c c o r d i n g 	 t o 	 t h e i r 	 s i z e 	 a n d	
pr ocessing	 c apabilities.
IntroduCtIon
The computer is just a dead collection of plastic, silicon and metal until you press the 
‘Power’ button. One little burst of electricity and it starts a string of events that puts life 
and power into the machine. But, even at this stage, the computer is unaware of the 
potential that it holds within itself. The computer, today, is a fundamental part of the 
information age. 
Initially, computers were developed to perform mathematical operations, but later on, they 
were used to store the result of those operations, which with the time leads to the storage 
of other data or information.
As we are talking about data and information, now we will learn what data is and what 
is called as information?
d ata is a collection of unprocessed facts, figures, and symbols.
e.g. Ram, age, 32, years, old
2
Information and Computer Technology
information is a processed form of data. It is organized, meaningful, and useful.
e.g. Ram is 32 years old.    Or    Ram’s age is 32 years.
A computer can be defined as an advanced electronic device that takes raw data as input 
from the user. It uses a set of instructions (called program) to process the data and give 
the result (output). The result can be used immediately or saved for future use.
1. Hardware and Software
In the process of converting data to information, a computer uses hardware and software. 
At the simplest level, all computers consist of these two basic components; the hardware 
and the software. 
h ardware is any part of the computer that has a physical structure that can be seen and 
touched, though some may be so tiny that they are invisible to the naked eye. 
s oftware is the instruction set that tells the computer how to perform tasks. Software is 
intangible i.e., that cannot be seen and touched, but its effect is clearly defined.
Input devices, output devices, a system unit, storage devices, and communication devices 
are all components of computer hardware. 
1.1  Hardware components are classified into following categories
I. Input devices 
input devices are the devices that allow a user to enter data and instructions into a 
computer such as keyboard, mouse, microphone, scanner, trackball, joystick, graphics 
tablet and digital camera.
The various functions of input devices are:
 ? They accept data and instructions from the user.
 ? They convert these instructions and data from human readable form to machine 
readable form.
 ? They supply the converted instructions and data to the CPU for further  
processing.
3
Computer and its Components
II. output devices
Output devices are used to display the result or information to the user through monitor 
or VDUs, LCDs, printers, plotters and speakers. 
Functions of output devices can be summed up as follows:
 ? It accepts the results produced by the computer which is in the coded form or machine 
readable form.
 ? It converts these coded results into human readable form.
 ? It supplies the converted results to the user.
Monitor or VDU Printers Plotters Speaker
III. Storage devices
s torage devices are the devices which are used to retrieved from and saved to the data 
and information such as hard drives, memory sticks (pen drives), compact discs, DVDs 
and tape drives.
Mouse
Trackball
Keyboard
Joystick
Microphone
Graphics Tablet
Scanner
Digital Camera
Page 4


1
Computer and its Components
Chapter 1
Computer and its Components
Learning Objectives 
By the end of this chapter, learner will be able to:
•	 Lis t	 fiv e	 c omput er	 applic a tions	 which	 ar e	 used	 on	 the	 daily	 basis.
•	 Iden tif y	 the	 diff er en t	 Input	 /	 Output	 de vices.	
•	 Describe	 the	 pr ocess	 of	 changing	 da t a	 fr om	 input	 t o	 output	 (The	 IPO	 cy cle).
•	 Explain	 the	 c onnectivity	 of	 de vices	 thr ough	 diff er en t	 kinds	 of	 ports.	
•	 Diff er en tia t e	 be tw een	 primar y	 and	 sec ondar y	 memor y .
•	 St a t e	 the	 purpose	 of	 diff er en t	 softw ar es.
•	 T a b u l a t e 	 t h e 	 d i ff e r e n c e 	 b e t w e e n 	 d i ff e r e n t 	 t y p e s 	 o f 	 c o m p u t e r s 	 a c c o r d i n g 	 t o 	 t h e i r 	 s i z e 	 a n d	
pr ocessing	 c apabilities.
IntroduCtIon
The computer is just a dead collection of plastic, silicon and metal until you press the 
‘Power’ button. One little burst of electricity and it starts a string of events that puts life 
and power into the machine. But, even at this stage, the computer is unaware of the 
potential that it holds within itself. The computer, today, is a fundamental part of the 
information age. 
Initially, computers were developed to perform mathematical operations, but later on, they 
were used to store the result of those operations, which with the time leads to the storage 
of other data or information.
As we are talking about data and information, now we will learn what data is and what 
is called as information?
d ata is a collection of unprocessed facts, figures, and symbols.
e.g. Ram, age, 32, years, old
2
Information and Computer Technology
information is a processed form of data. It is organized, meaningful, and useful.
e.g. Ram is 32 years old.    Or    Ram’s age is 32 years.
A computer can be defined as an advanced electronic device that takes raw data as input 
from the user. It uses a set of instructions (called program) to process the data and give 
the result (output). The result can be used immediately or saved for future use.
1. Hardware and Software
In the process of converting data to information, a computer uses hardware and software. 
At the simplest level, all computers consist of these two basic components; the hardware 
and the software. 
h ardware is any part of the computer that has a physical structure that can be seen and 
touched, though some may be so tiny that they are invisible to the naked eye. 
s oftware is the instruction set that tells the computer how to perform tasks. Software is 
intangible i.e., that cannot be seen and touched, but its effect is clearly defined.
Input devices, output devices, a system unit, storage devices, and communication devices 
are all components of computer hardware. 
1.1  Hardware components are classified into following categories
I. Input devices 
input devices are the devices that allow a user to enter data and instructions into a 
computer such as keyboard, mouse, microphone, scanner, trackball, joystick, graphics 
tablet and digital camera.
The various functions of input devices are:
 ? They accept data and instructions from the user.
 ? They convert these instructions and data from human readable form to machine 
readable form.
 ? They supply the converted instructions and data to the CPU for further  
processing.
3
Computer and its Components
II. output devices
Output devices are used to display the result or information to the user through monitor 
or VDUs, LCDs, printers, plotters and speakers. 
Functions of output devices can be summed up as follows:
 ? It accepts the results produced by the computer which is in the coded form or machine 
readable form.
 ? It converts these coded results into human readable form.
 ? It supplies the converted results to the user.
Monitor or VDU Printers Plotters Speaker
III. Storage devices
s torage devices are the devices which are used to retrieved from and saved to the data 
and information such as hard drives, memory sticks (pen drives), compact discs, DVDs 
and tape drives.
Mouse
Trackball
Keyboard
Joystick
Microphone
Graphics Tablet
Scanner
Digital Camera
4
Information and Computer Technology
 1. Floppy disks were developed in late 1960s. A floppy disk is made up 
of a circular thin plastic jacket coated with magnetic material. Its outer 
cover which is a hard plastic protects this plastic disk. It can hold 1.44 
MB data. Nowadays, these disks are outdated. 
 2. h ard disk is made up of a metal disk and coated with a 
metal oxide used to store bulk of data. These disks can store 
more information than floppy disks, up to tens or hundreds 
of gigabytes. 
Cover Mounting Holes 
(Cover not shown)
Case Mounting Holes
Ribbon Cable (attaches 
heads to Logic Board)
Platters
Power Connector
Base Casting
Spindle
Slider (and Head)
Actuator Arm
Actuator Axis
Actuator
SCSI Interface Connector
Jumper
Jumper Pins
 3. Compact disk – r ead only Memory or CD-ROM is a read only or read-write disk. 
It can store large amount of data which can be distributed to large number of users. 
It is inexpensive and fast, but its access time is longer than that of magnetic disk. 
  There are two types of CDs:      CD-R and CD-RW . 
  CD-R stands for Compact Disk – Recordable which can store 700 
MB of data, but only once. 
  CD-RW stands for Compact Disk – ReWriteable which can read, 
write and erase data as many times. 
 4. dvd , short for Digital Versatile Disc, is an optical storage disc similar 
to CD-ROM, as this is double sided with dual layer disc and can hold 
4.7 GB of data. 
 5. blue-r ay disks are used to store more than 25 GB of data with a very high speed 
in less amount of time. A single layer of BD can store 13 hours of video where as 
double layer BD can store more than 20 hours of video.
Page 5


1
Computer and its Components
Chapter 1
Computer and its Components
Learning Objectives 
By the end of this chapter, learner will be able to:
•	 Lis t	 fiv e	 c omput er	 applic a tions	 which	 ar e	 used	 on	 the	 daily	 basis.
•	 Iden tif y	 the	 diff er en t	 Input	 /	 Output	 de vices.	
•	 Describe	 the	 pr ocess	 of	 changing	 da t a	 fr om	 input	 t o	 output	 (The	 IPO	 cy cle).
•	 Explain	 the	 c onnectivity	 of	 de vices	 thr ough	 diff er en t	 kinds	 of	 ports.	
•	 Diff er en tia t e	 be tw een	 primar y	 and	 sec ondar y	 memor y .
•	 St a t e	 the	 purpose	 of	 diff er en t	 softw ar es.
•	 T a b u l a t e 	 t h e 	 d i ff e r e n c e 	 b e t w e e n 	 d i ff e r e n t 	 t y p e s 	 o f 	 c o m p u t e r s 	 a c c o r d i n g 	 t o 	 t h e i r 	 s i z e 	 a n d	
pr ocessing	 c apabilities.
IntroduCtIon
The computer is just a dead collection of plastic, silicon and metal until you press the 
‘Power’ button. One little burst of electricity and it starts a string of events that puts life 
and power into the machine. But, even at this stage, the computer is unaware of the 
potential that it holds within itself. The computer, today, is a fundamental part of the 
information age. 
Initially, computers were developed to perform mathematical operations, but later on, they 
were used to store the result of those operations, which with the time leads to the storage 
of other data or information.
As we are talking about data and information, now we will learn what data is and what 
is called as information?
d ata is a collection of unprocessed facts, figures, and symbols.
e.g. Ram, age, 32, years, old
2
Information and Computer Technology
information is a processed form of data. It is organized, meaningful, and useful.
e.g. Ram is 32 years old.    Or    Ram’s age is 32 years.
A computer can be defined as an advanced electronic device that takes raw data as input 
from the user. It uses a set of instructions (called program) to process the data and give 
the result (output). The result can be used immediately or saved for future use.
1. Hardware and Software
In the process of converting data to information, a computer uses hardware and software. 
At the simplest level, all computers consist of these two basic components; the hardware 
and the software. 
h ardware is any part of the computer that has a physical structure that can be seen and 
touched, though some may be so tiny that they are invisible to the naked eye. 
s oftware is the instruction set that tells the computer how to perform tasks. Software is 
intangible i.e., that cannot be seen and touched, but its effect is clearly defined.
Input devices, output devices, a system unit, storage devices, and communication devices 
are all components of computer hardware. 
1.1  Hardware components are classified into following categories
I. Input devices 
input devices are the devices that allow a user to enter data and instructions into a 
computer such as keyboard, mouse, microphone, scanner, trackball, joystick, graphics 
tablet and digital camera.
The various functions of input devices are:
 ? They accept data and instructions from the user.
 ? They convert these instructions and data from human readable form to machine 
readable form.
 ? They supply the converted instructions and data to the CPU for further  
processing.
3
Computer and its Components
II. output devices
Output devices are used to display the result or information to the user through monitor 
or VDUs, LCDs, printers, plotters and speakers. 
Functions of output devices can be summed up as follows:
 ? It accepts the results produced by the computer which is in the coded form or machine 
readable form.
 ? It converts these coded results into human readable form.
 ? It supplies the converted results to the user.
Monitor or VDU Printers Plotters Speaker
III. Storage devices
s torage devices are the devices which are used to retrieved from and saved to the data 
and information such as hard drives, memory sticks (pen drives), compact discs, DVDs 
and tape drives.
Mouse
Trackball
Keyboard
Joystick
Microphone
Graphics Tablet
Scanner
Digital Camera
4
Information and Computer Technology
 1. Floppy disks were developed in late 1960s. A floppy disk is made up 
of a circular thin plastic jacket coated with magnetic material. Its outer 
cover which is a hard plastic protects this plastic disk. It can hold 1.44 
MB data. Nowadays, these disks are outdated. 
 2. h ard disk is made up of a metal disk and coated with a 
metal oxide used to store bulk of data. These disks can store 
more information than floppy disks, up to tens or hundreds 
of gigabytes. 
Cover Mounting Holes 
(Cover not shown)
Case Mounting Holes
Ribbon Cable (attaches 
heads to Logic Board)
Platters
Power Connector
Base Casting
Spindle
Slider (and Head)
Actuator Arm
Actuator Axis
Actuator
SCSI Interface Connector
Jumper
Jumper Pins
 3. Compact disk – r ead only Memory or CD-ROM is a read only or read-write disk. 
It can store large amount of data which can be distributed to large number of users. 
It is inexpensive and fast, but its access time is longer than that of magnetic disk. 
  There are two types of CDs:      CD-R and CD-RW . 
  CD-R stands for Compact Disk – Recordable which can store 700 
MB of data, but only once. 
  CD-RW stands for Compact Disk – ReWriteable which can read, 
write and erase data as many times. 
 4. dvd , short for Digital Versatile Disc, is an optical storage disc similar 
to CD-ROM, as this is double sided with dual layer disc and can hold 
4.7 GB of data. 
 5. blue-r ay disks are used to store more than 25 GB of data with a very high speed 
in less amount of time. A single layer of BD can store 13 hours of video where as 
double layer BD can store more than 20 hours of video.
5
Computer and its Components
 6. usb stands for Universal Serial Bus. It is a portable memory device 
which is used to store data that needs to be transferred to the other 
device using USB port of the system. 
 7. Memory Card or flash memory card is a memory device. It is used as 
an easy, fast and reliable medium to store and transfer data from one 
device to the other. It is used in digital cameras, game consoles, mobile 
phones etc.
1.2. CPu (Central Processing unit)
The system unit is the box that protects the internal electronic components from damage. 
It contains the central processing unit (CPU) and memory. The CPu interprets and 
carries out the basic instructions that operate the computer. Memory is where data and 
instructions are held.
The heart of the computer system is the processor unit. It consists of the a rithmetic and 
l ogic u nit (alu) which executes most computer operations (arithmetic and logical) 
and the Control u nit which acts as the nerve centre that sends control signal to all other 
units.
The control unit and ALU are usually many times faster than other devices connected to a 
computer system. This enables a single processor to control a number of external devices 
such as video terminals, magnetic tapes, disk memories, sensors, displays and mechanical 
controllers, since they are much slower than the processor.
1.3. Memory
There are two categories of memory, primary memory and secondary memory (or external 
memory). 
Primary Memory is very fast as data and programs must be in the primary memory for 
execution. Random Access Memory (RAM) and Read Only Memory (ROM) are both 
primary memory. 
r andom a ccess Memory refers to memory that can be selected and used randomly. The 
information stored here disappears the very moment the machine is turned off. It is also 
referred to as volatile memory.
r ead only Memory is permanently built into the computer at the time of production. 
The information from this memory can only be read and it is not possible to write fresh