Elements Of A Computer System (Classification, Characteristic, Limitations)

Elements Of A Computer System

Definition of a Computer:

 A computer is an electronic device that operates under the control of a set of instructions that is stored in its memory unit.

 A computer is a collection of hardware and software components that help you complete many different tasks.

 A computer can be more accurately defined as an electronic device that takes data as input, stores and processes it and displays the output according to the given instructions.

Characteristics of computer

Computers of all sizes have common characteristics:–
 Speed
 Reliability
 Multitasking
 Diligence
 Accuracy
 Memory capacity

 It works in very high speeds and can much faster than human.
 It equivalent to one million mathematicians working 24 hours in a day.

 Computers are extremely reliable as well. Most errors are caused by humans, not computers.
 Computers are capable of storing enormous amounts of data that must be
located and retrieved very quickly.

 Modern computers can perform multiple task at once. i.e. they can perform a set of works simultaneously .
 Example – at a same time it can play a game & printing your document.

 Unlike human, computer simply does not get bored or tired.
 Repetitive work does not affect computer.

 Computers rarely make mistakes.
 Most computer errors are caused by human faults

Storage capacity
 It stores huge amount of data / information

Classification ofComputers

Computers can be classified many different ways — by size, by function, or by processing capacity.

Functionality wise 4 types
a) Micro computer
b) Mini Computer
c) Mainframe Computer
d) Super Computer


 Microcomputers are connected to networks of other computers.
 The price of a microcomputer varies from each other depending on the capacity and features of the computer.
 Microcomputers make up the vast majority of computers.
 Single user can interact with this computer at a time.
 It is a small and general purpose computer.

Mini Computer

 Mini Computer is a small and general purpose computer.
 It is more expensive than a micro computer.
 It has more storage capacity and speed.
 It designed to simultaneously handle the needs of multiple users.

Mainframe Computer

 Large computers are called Mainframes.
 Mainframe computers process data at very high rates of speed, measured in the millions of instructions per second.
 They are very expensive than micro computer and mini computer.
 Mainframes are designed for multiple users and process vast amounts of data quickly.
 Examples :- Banks, insurance companies, manufacturers, mail-order companies, and airlines are typical users.

Super Computers

 The largest computers are Super Computers.
 They are the most powerful, the most expensive, and the fastest.
 They are capable of processing trillions of instructions per second.

It use governmental agencies, such as:

 Chemical analysis in laboratory
 Space exploration
 National Defense Agency
 National Weather Service
 Bio-Medical research
 Design of many other machines

Limitations of Computer

Computer cannot operate without the instructions given by humans. It is programmed to work effectively, fast and accurately. Computer cannot think by itself and does not have common sense. It is totally dependent on humans.

  • Depend on users input.
  • Computer have no imagination.
  • Cannot detect error in logic.
  • Only expert user can work on it.
  • Cannot take its own decisions.

Some of the limitations of computer are as follows:

No Self-Intelligence

Computer does not have intelligence of its own to complete the tasks. They give wrong output if the input given by humans are wrong. It works according to the instructions given to it by the user.

No Thinking and Decision Making Power

The computer cannot think itself. The concept of artificial intelligence shows that computer can think. But still this concept is dependent on set of instructions. It cannot take any decision. It can only perform the tasks that are instructed by the users.

No Feeling

Lack of feeling is another limitation of computer. A computer cannot feel like us. It does not have emotions, feelings, knowledge etc. It does not get tired and keep on doing its tasks. It can do very risky works which are not capable by human beings.

No Learning Power

Computer has no learning power. Computer cannot perform the tasks without instructions. It cannot read the same instructions time and again. Once the instructions is given it will work for one time. It can solve the problems but it cannot learn the problems. It can only work according to the instructions given.

More, limitation of computer

Computer has done this and that. Actually this is not the computer which has done this but the user. Despite its various features, a computer does have the following limitations:

a. No Self Intelligence
Today, a computer is able to do a work which is impossible for man. Computers are used to do risky and dangerous work and where sharp actually is needed. But it does not have any intelligence of its own. It works according to the instruction only.

b. No Decision-Making power
Computer cannot take any decision of its own. It does only those tasks which are already instructed to it.

c. No learning power
Computer has no learning power. Once you give instructions to a computer how to perform a task, the very task is cannot perform if you do not give it any instructions for the next time. For example, when you are taught how to solve a problem and it same type of problem is given to you to solve, then you can do it because you have learned how to solve the problem.


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