The document provides an overview of computer systems. It defines a computer as an electronic device that can receive and process data according to programmed instructions to produce useful information. It works through an input-process-output cycle, taking in data, manipulating it via the central processing unit (CPU) which contains an arithmetic logic unit and control unit, and outputting the results. The CPU acts as the computer's brain. The document also outlines the basic components of a computer system including input, output, storage, and processing units, as well as characteristics, limitations, applications, and trends in technological convergence.

1. Ch - 1
Computer
System – An
Overview

2. Introduction
 Computers, these days, have become an
essential part of our day-ta-day life.
 The word Computer is derived from Latin
word Computare, which means to Count or
Compute. So the word Computer can be
used for any device that can perform
calculations.
 It can also process various types user data
and that too with 100% accuracy.

3. What is Computer?
An electronic device which is capable
of receiving information (data) in a
particular form and of performing a
sequence of operations in
accordance with a predetermined but
variable set of procedural instructions
(program) to produce a result in the
form of information or signals.

4. Input
Process
Output

5. Functioning of the Computer
System
Input: Accepts data and instructions.
Processing: Manipulates data as per
instructions
Output: Produces desired
output/information.
Storage: Stores data, instructions and
information.

6. Basic Structure
CPU
CU
ALU
OutputInput
Memory Unit
External Memory

7. Input Unit
Data and Instruction are entered in the
computer systems with the help of input unit,
which act like a link between user and
computer. Different types of input units are
used with the computer depending on the
type of data or the format of the instructions
to be given to the computer like keyboard,
mouse, scanner, microphone, etc. It converts
the data into the binary form and stores it into
the main memory of the computer.

9. Processing Unit
Data in the computer is
processed by the Central
Processing Unit (CPU)
which is also known as
the brain of the computer.
It mainly comprises of two
units ALU (Arithmetic and Logical Unit) and CU
(Control Unit). All types of data processing are
carried out by the ALU whereas CU helps to control
the flow of data in the system from one part to
another.

10. Output Unit
Once the data is processed, the results are
stored back into the main memory of the
system which is received by the users on the
output unit. The information stored in the
binary form inside the computer is converted
into the user readable form before it appears
on the output unit. Commonly used output
devices are VDU or monitor, printer, speaker,
plotter, etc.

12. Storage Unit
This is also known as the memory unit where
data and information are stored temporarily
in binary form. This is the main memory of the
system which is like a storage brain of the
computer. It interacts directly with the CPU to
provide the required data and instructions
and to get back the processed information. It
also interacts with the external memory for
storing the information permanently and to
retrieve the stored information in it.

14. Characteristics of Computer
Computers can perform highly complex tasks with
great ease and accuracy which are difficult for
human being to perform. Some are as follows:
 Speed
 Accuracy
 Diligence
 High Storage Capacity
 Versatility

15. Limitations of the Computer
 Zero IQ
 Lack of Decision Making Power
 No Learning Power

16. Applications of a Computer
Computers, nowadays are widely used in a variety of
fields because of the advantages like quick processing
and ability to process different types of data with an
ease. Some of the major areas of computer applications
are listed below:
 Business
 Research
 Education
 Communication
 Defence
 Medicines and Healthcares
 Entertainment
 Computer Aided Manufacturing (CAM
 Simulation
 At Home

17. Convergence of Technologies
Technological convergence is the process by which
existing technologies merge into new forms that
bring together different types of media and
applications. New devices and technology usually
handle one medium or accomplish some basic
tasks; through technological convergence, devices
can interact with a wider array of media types. For
example, a new type of media storage often require
new players that only play that format. As the
technology advances, however, new models might
include additional features like the ability to
interface with more devices or play other types of
media.

19. LETS’S SUMMARIZE
 Computer is an electronic device which
converts raw data into useful information as
per user’s instructions.
 Computer works on the principle of Input –
Process – Output, i.e., IPO cycle.
 CPU is the main data processing unit also
known as the brain of the computer.
 ALU and CU are the main components of
CPU.

21. Made by –
Hitesh Singh
IX A 20