2. Table of Contents
Computer
Computer Operations
o Input
o Output
o Processing
o Storage
Characteristics of Computer
Computer Hardware
Computer Software
Hardware vs Software
3. Computer
Definition:
o A computer is an electronic device that accepts input,
stores and manipulates data according to list of
instructions given by user.
o An electronic device designed to accept data,
perform prescribed mathematical and logical
operations at high speed, and display the results of
these operations.
o It has the ability to Store, Retrieve, and Process data.
4. Computer Operations
The computer is an electronic machine that performs the
following four general operations:
o Input
o Processing
o Storage
o Output
5. Input:
Information and programs are entered into the computer
through Input devices such as the keyboard, disks, or through
other computers via network connections or modems connected
to the Internet.
Processing:
The CPU or central processing unit is sometimes called the
Control Unit and directs the operation of the input and output
devices. It contains the electronic circuits that cause the computer
to follow instructions from ROM (Read Only Memory) or from a
program in RAM (Random Access Memory).
6. Storage:
Secondary storage devices are used to store instructions
and data when they are not being used in memory. Two types of
storage more often used on personal computers are floppy disks
and hard disks.
Output:
Output devices such as a monitor or printer make
information you input available for you to view or use. They also
display messages about what errors may have occurred and
brings up message or dialog box asking for more information to
be input.
7. Characteristics of Computer
1. Speed:
Internal processes of computer operate at the speed of light,
limited only by the program that control these processes and the
quantum of data under the speed with which computers perform
is wat beyond human capabilities. The speed of computer is
calculated in milliseconds(10-3).
2. Accuracy:
The Accuracy of a computer is consistently high. Error can
occur but these are almost always due to human error rather than
technological weaknesses. Computer errors arise due to incorrect
data input or unreliable program are often referred to as
GIGO(garbage- in garbage -out)
8. 3. Storage:
A computer can store large amount of data. This data can
be used at any time and also from any location. The storage
capacity of a computer is measured in Mega Byte, Gega Byte,
Tera Byte.
4. Versatility:
Computer is a versatile machine. They are used in various
fields. They are used in Schools & Colleges, at hospitals, at
government organizations and at home for entertainment & work
purposes.
5. Reliability:
Computers are very reliable. The electronic components in
modern computer rarely break or fail.
9. 6. Communication:
Computers have the ability to communicate but of course
they needs some sort of connection either Wired or Wireless
connection. Two computers can be connected to send & receive
data.
7. Multi-tasking:
Computers can perform several tasks at a time. For
example you can listen to songs, download movies, and prepare
word documents all at the same time.
10. 8. Automation
Computers are quite capable of functioning
automatically, once the process is given to the computer. They do
not require any instruction from the operator at any stage of the
process.
9. Cost Reductions:
We can perform difficult tasks in less time and less cost.
For example: we may have to hire people to handle an office. The
same work can be performed by a single person with help of
computer.
10. Power to remember:
It has the power to remember our data.
11. Computer Hardware
Hardware:
o Physically connected to the computer or something that
can be physically touched.
o A CD-ROM, computer display monitor, printer, and video
card are all examples of computer hardware.
o The hardware of a computer is infrequently changed, in
comparison with software and data, which are “soft” in
the sense that they are readily created, modified or
erased on the computer.
12. Computer Software
Software:
o Software is a general term used to describe a collection
of computer programs, procedures, and documentation
that perform some task on a computer system.
o Computer systems divide software systems into three
major classes :
System software
Programming software
Application software.
