Computer Performs only Three Basic Functions
1. Arithmetic calculations i.e., Addition, Subtraction, Multiplications and Division;
2. Compare Values
3. Store, Search and Retrieve
It should be very clearly understood that although computer essentially does all above functions automatically, it does not possess any intelligence of its own. Its intelligence quotients or I.Q. is zero i.e. it does not have any thinking, arguing or decision-taking power of its own. This power is intelligently conferred to it by proper programming methods by persons handling it. Let us see where computer stands in comparison to human brain.
The Characteristics of a Computer:
Computers display following characteristics to a greater or lesser extent depending on their type and application. Computers are not merely calculators but are programmable calculators which help to reduce the burden on human memory and burden of mechanical processing. Computers have assumed their importance due to following capabilities.
Computers make calculations at very fast rate. But how fast? Let s multiply 383 with 186. It takes about 60 seconds for expert calculator to do this job with the help of pencil, his wisdom and memory. Similarly think how long it would take you to count up to 2 million 20 lakhs? Try! Though you are quick at counting numbers, even then it will take about a minute in counting upto 100 numbers. With this speed it will take over a week of your continuous counting. But a modern computer can do 20, 000, 000 twenty million or 2 crore such calculations in one minute and those too, without any mistake. A computer deals with that amount of arithmetic jugglery in a minute which will take entire life of a man expected to live long upto 100 years.
Super High Accuracy and Degree of Reliability:
Computers are designed in such a way that their individual components have very high life and degree of reliability. All mechanical parts have super high endurance capacity so that computer works without tiring. It works on the basis of electric pulses due to which there is no chance of its making mistakes. It can repeat the same job a number of times in exactly the same way.
Storage Capacity or Memory:
The computers have got superb inbuilt and auxiliary memory systems. A computer system can store a great amount of information in it. The success of computers lies not only in storing the information but also in the great speed of utilizing the memory storage. The computer at lightning speeds can retrieve any item of data or any instruction stored in memory. Modern computer can call back any data out of its stored memory in few nanoseconds. 1 nanosecond is 1 million times smaller than 1000th part of second i.e. 1 nanosecond= 0.000000001 second. The idea of computer having memory was encapsulated by the great scientist john von- Neumann in 1946 who was working on an atomic bomb project.
It is the ability to take in and store a sequence of instruction for obeying. Such a sequence of instructions is called a program and must be written in the languages of computer. It is also the ability to obey a sequence of program instructions, provided the instructions are stored within the computer. The program instructions will be obeyed in sequence automatically, without the need for manual intervention at each step. This very different from the operation of a typical pocket calculator which needs buttons to be pressed for each operation and where the person using the calculator controls the sequence of operations.