is an electronic machine capable of accepting
data arithmetically and logically,
from the processing, and storing
for future use.
The first three operations in the information processing cycle which include input, process, and output are performed
to process data into information, while the fourth operation, storage refers to a computer's electronic reservoir
A computer is an electronic device, operating under the control of instructions (software) stored in its own memory unit, that can accept data (input), manipulate data (process),
and produce information (output) from the processing. Generally, the term is used to describe a collection of devices that function together as a system.
Data and Information
Raw facts that are not yet processed. include numbers , letters and symbols etc.
This is the end product of data processing stages which have been transformed and have clear meaning to the user.
Components of computer
Computer components are divided into major categories :-
- Live ware (People)
Hardware : Is the machine itself and its connected devices such as Monitor, Motherboard, Mircoprocessor, Primary Storage (RAM)
, Expansion cards, Power supply, Optical disc drive, Secondary Storage (Hard disk), System Case, Keyboard, Mouse etc.
Software : Are the set of programs that make use of hardware for performing various functions.
So, without softwares computer system will not be able to work.
Live ware : These can be termed as the people and other consumable which make use of the computer.
Categories and Classification of Computers (Types of a computers)
Computers are classified into different types depending on the memory size, cost and processing speed.
- Classification by size / capacity
- Mainframe computers
- Mini computers
- Micro computers
- Super computers
- Classification by function (process)
- Analog computers (Special purpose)
- Digital computers (General purpose )
- Hybrid computers
- By technological generation (Computer Generations)
- First technology uses vacuum tube
- Second technology uses transistors, capacitors, resistors.
- Third technology uses integrated circuits - ICs
- Fourth Generation uses Processor
- Fifth Generation uses Artificial Intelligence
Advantages of using a computer
Speed : Can process work within a short time that could be done by so many people and therefore it is time
Accuracy : The way you type in data is the way it appears
Storage : It can store a large information in a limited space
Secrecy : Information is fairly protected if the computer is well managed
Reference : One can store documents for future use
Security : Information can be prevented from being accessed by the unauthorized personnel through the use
Quality of presentation : Work in a computer can be presented in various ways and can as well be transmitted
easily. Also font style are readable than human writings.
Entertainment tool :It can be used as an entertainment tool
Higher memory capacity : It has a higher memory compared to human beings
Disadvantages of using a computer
Unemployment : Only the skilled continues with job. It does work that could be instead done by many people
Cost : The cost of running a computer or any associated information system is high especially to small
Health hazard : Can cause eye problems
Virus attack : This may cause the loss of vital information stored in computer at any time
Expensive to hire : Computers need experts for maintenance which is expensive to hire
Loss of information : If not well managed is easy.
Application of a computer
In institutions :It is used in teaching and learning process
Offices :It is used for data management
Hospitals :It is used for monitoring patients and records management
Airports :It is used for aircrafts management
Factories or industries :It is used for driving machines and car assembles (robots)
Supermarkets :It is used for stock control
Banks :It is used for deposits, withdrawals, balances etc.
Transport :It is used for monitoring vehicle traffic on a busy town , aircraft
Communication :It is used for message transmission from one person to another efficiently and effectively
Law enforcement agencies :information held in computers such as fingerprints, photographs and other
identification details helps law enforcers to carry out criminal investigations speedily
Domestic and entertainment : It is used for creating movies etc.
Library services : In computerized library, a computer enables library personnel to easily access and keep
update records of book.
Cartoon Film Production
Payment of electricity and telephone lines
Operations or functions of a computer
A computer performs five major operations or functions irrespective of its size and make. These are :-
It accepts data or instructions as input
It stores data and instruction
It processes data as per the instructions
It controls all operations inside a computer and
It gives results in the form of output
Characteristics of a computer
The characteristics of computers that have made them so
powerful and universally useful are speed, accuracy,
diligence, versatility and storage capacity.
Computers work at an incredible speed. A powerful computer
is capable of performing about 3-4 million simple instructions
In addition to being fast, computers are also accurate. Errors
that may occur can almost always be attributed to human
error (inaccurate data, poorly designed system or faulty
instructions/programs written by the programmer)
Unlike human beings, computers are highly consistent. They
do not suffer from human traits of boredom and tiredness
resulting in lack of concentration. Computers, therefore, are
better than human beings in performing voluminous and
Computers are versatile machines and are capable of
performing any task as long as it can be broken down into a
series of logical steps. The presence of computers can be
seen in almost every where like Railway and Air reservation, Banks,
Hotels, Weather forecasting and many more.
Storage Capacity :
Today's computers can store large volumes of data. A piece
of information once stored in the computer,
can never be forgotten and can be retrieved almost
Limitations of a computer
- Computer needs clear and complete instructions to perform a task accurately. If the instructions
are not clear and complete, the computer will not produce the required result.
- Computer can not think.
- Computer can not learn by experience.