UNIT 1
COMPUTER SYSTEM AND
ORGANISATION
CLASS XII
COMPLETE NOTES AND IMPORTANT
QUESTIONS
CHAPTER WISE
MINI CHITRA
,TABLE OF CONTENTS
INTRODUCTION TO COMPUTER SYSTEMS 2
DATA AND INFORMATION 3
FUNCTIONAL COMPONENTS 3
IMPORTANT QUESTIONS ON FUNCTIONAL COMPONENTS 5
MEMORY IN A COMPUTER SYSTEM 18
IMPORTANT QUESTIONS ON MEMORY IN A COMPUTER SYSTEM20 20
UNITS OF MEMORY 33
IMPORTANT QUESTIONS ON UNITS OF MEMORY 35
1
,UNIT 1: COMPUTER SYSTEMS AND ORGANISATION
[BASIC COMPUTER ORGANISATION]
INTRODUCTION TO COMPUTER SYSTEM
A computer system is a combination of hardware, software, and peripheral devices that
work together to perform various operations, including data input, processing, output,
storage, and communication. The components of computer system are:
Hardware: The physical components of a computer system, such as the central
processing unit (CPU), memory, storage devices, input/output devices, and
communication devices.
Software: The programs and operating system that run on a computer system,
including application software, system software, and utility programs.
Peripheral devices: Additional devices such as printers, scanners, keyboards,
mice, and monitors that are used to extend the capabilities of the computer system.
The computer system works by taking input from the user, processing it through the CPU
and memory, storing the results in storage devices, and then providing output through
various output devices. The operating system controls the hardware and software
components of the computer system and provides a user-friendly interface for the user to
interact with the computer system.
Computer systems come in different sizes and types, from desktop computers and laptops
to servers and supercomputers. The type of computer system used depends on the intended
use and the processing power required.
2
, DATA AND INFORMATION
In a computer system, data refers to any raw or unprocessed value or figures that have no
meaning on their own. Data can be in the form of text, numbers, images, videos, and other
types of digital information.
On the other hand, information uses data to convert it into useful context. Information is
created by organizing, interpreting, and summarizing data in a way that can be easily
understood and used for decision-making or other purposes.
In summary, data is the raw material, while information is the processed and analysed
output that is useful and meaningful to the user.
FUNCTIONAL COMPONENTS OF A COMPUTER
A computer consists of several functional components that work together to perform
different tasks. The primary functional components of a computer are:
Central Processing Unit (CPU): It is the brain of the computer that performs all
the processing operations. It controls the execution of instructions and performs
arithmetic and logical operations on data.
Random Access Memory (RAM): It is a type of memory that stores data
temporarily while the computer is running. The CPU can access data stored in RAM
very quickly, making it an essential component for a computer's performance.
3
COMPUTER SYSTEM AND
ORGANISATION
CLASS XII
COMPLETE NOTES AND IMPORTANT
QUESTIONS
CHAPTER WISE
MINI CHITRA
,TABLE OF CONTENTS
INTRODUCTION TO COMPUTER SYSTEMS 2
DATA AND INFORMATION 3
FUNCTIONAL COMPONENTS 3
IMPORTANT QUESTIONS ON FUNCTIONAL COMPONENTS 5
MEMORY IN A COMPUTER SYSTEM 18
IMPORTANT QUESTIONS ON MEMORY IN A COMPUTER SYSTEM20 20
UNITS OF MEMORY 33
IMPORTANT QUESTIONS ON UNITS OF MEMORY 35
1
,UNIT 1: COMPUTER SYSTEMS AND ORGANISATION
[BASIC COMPUTER ORGANISATION]
INTRODUCTION TO COMPUTER SYSTEM
A computer system is a combination of hardware, software, and peripheral devices that
work together to perform various operations, including data input, processing, output,
storage, and communication. The components of computer system are:
Hardware: The physical components of a computer system, such as the central
processing unit (CPU), memory, storage devices, input/output devices, and
communication devices.
Software: The programs and operating system that run on a computer system,
including application software, system software, and utility programs.
Peripheral devices: Additional devices such as printers, scanners, keyboards,
mice, and monitors that are used to extend the capabilities of the computer system.
The computer system works by taking input from the user, processing it through the CPU
and memory, storing the results in storage devices, and then providing output through
various output devices. The operating system controls the hardware and software
components of the computer system and provides a user-friendly interface for the user to
interact with the computer system.
Computer systems come in different sizes and types, from desktop computers and laptops
to servers and supercomputers. The type of computer system used depends on the intended
use and the processing power required.
2
, DATA AND INFORMATION
In a computer system, data refers to any raw or unprocessed value or figures that have no
meaning on their own. Data can be in the form of text, numbers, images, videos, and other
types of digital information.
On the other hand, information uses data to convert it into useful context. Information is
created by organizing, interpreting, and summarizing data in a way that can be easily
understood and used for decision-making or other purposes.
In summary, data is the raw material, while information is the processed and analysed
output that is useful and meaningful to the user.
FUNCTIONAL COMPONENTS OF A COMPUTER
A computer consists of several functional components that work together to perform
different tasks. The primary functional components of a computer are:
Central Processing Unit (CPU): It is the brain of the computer that performs all
the processing operations. It controls the execution of instructions and performs
arithmetic and logical operations on data.
Random Access Memory (RAM): It is a type of memory that stores data
temporarily while the computer is running. The CPU can access data stored in RAM
very quickly, making it an essential component for a computer's performance.
3
