Introduction to Computer

Computer is a machine that performs calculation and processes information with  great accuracy and speed. It can handle vast amount of information and solve complicated problems. The powerful computers can perform billions of calculation per second. The two principal characteristics of computer are :

1. It responds to specific set of instructions in a well-defined manner.
2. It can execute a prerecorded list of instruction (program).

Importance of Computer

With the help of computers, we can simplify difficult or time-consuming tasks. These tasks are :

1. Solving numerical problems :  With the help of computers, the numerical complicated problems can be completed easily. Such problems mainly occurs in scientific research or in huge mathematical calculations.
2. Storing and retrieving information : Information stored in a computer is called database. Computer nowadays are used to store small to huge amount of data. Example : country census data, etc.
3. Creating & Displaying documents and pictures : Computer can store huge no. of words in such a way that makes it easy to manipulate them. Example : Microsoft Words.

Characteristics of Computer

1. Word-length
2. Speed
3. Storage
4. Accuracy
5. Versatility
6. Automatic
7. Diligence 

Word-length : A computer operates on binary digits - '0' and '1'. A group of 8-bit is called a byte. The number of bits that a computer can process at any given time is called it's word-length. Word-length is computing power of computer. Commonly used word-length are : 8, 16, 32, 64. Example : When we say 64-bit Windows, it means that the word-length is 64.

Speed : Computers can calculate at very high speed. For example : super computers can operate at speed measured in nanoseconds or even in pico-seconds.

• 1 millisecond = 10^-3 seconds
• 1 microsecond = 10^-6 seconds
• 1 nanosecond = 10^-9 seconds
• 1 picosecond = 10^-12 seconds 

Storage : Computer have main memory and auxiliary memory which helps to store large amount of data. The factors that makes computer storage unique is not only storing power but also the fact that it can retrieve information that users wants in matter of seconds.

Accuracy : Computer can process a information in high accuracy. There is no chance of computer that it gives wrong output. As we know 'GIGO [Garbage In Garbage Out]', computer only displays wrong output when the input is wrong. Computer can perform complicated operations accurately and in high speed.

Versatility : Computer can run multiple tasks at a time. It has ability to process more than one information at a time. For example : a user can listen to music, create documents, upload/download, all at a same time.

Automatic : Computer is an automatic machine. A user just has to give a command to it and all the information are processed automatically by the machine. Such characteristic of computer is Automatic. For example : a user just gives a command to calculate something and the computer automatically calculates it and displays the result.

Diligence : Computer is never tired of doing same task again and again. Computer does not display bored or tired message of doing same task again and again. The same task can be processed infinite times by the computer, which is known as diligence.