CHAPTER 1 : COMPUTER BASICS 

Definition of Computer

The origin of the word computer is taken from Latin word “Computer”, meaning “to calculate”. So, according to this definition, Computer is a machine which can perform calculations at very high speed. In other words, Computer is an electronic device which converts raw data into meaningful information. A computer is an electro mechanical device which, accepts data, stores and processes the data and gives out meaningful information at a very high speed with accuracy. So it can be said, Computer is a digital and automatic machine that takes data as input from the users, processes it, stores it if necessary and gives output in desired form.

Standard Definitions of a Computer

“A device used for computing; specifically, an electronic machine which, by means of stored instructions and information, performs rapid, often complex calculations or compiles, correlates and selects data”.   – Webster’s Dictionary

“A data processor that can perform substantial computation, including numerous arithmetic and logic operations, without intervention by a human operator during the run”.

– International Standards Organisation (ISO)

“A device capable of solving problems by accepting data, performing described operations on the data and supplying the results of these operations”.  – US Institute of Computer Sciences

Characteristics of Computer

Today the computer plays a major role in the modern society and its development. The characteristics that make a computer possible to play such vital role are:

• High Speed: Since electrical pulses cause all the operations of the computer, the computers can perform large number of operations in just one second. The processing speed of a computer is generally measured in Nano seconds. Since the computers are electronic device and work with the electrical pulses which travel at incredible speed and hence their internal speed is also virtually instantaneous. The speed of the processing varies with the computer
• Accuracy: The accuracy of the computers is consistently very high. Computers do not make mistakes. Errors causes in computing are generally due to negligence, such as inaccurate data, improper procedures, poor designs,
• Storage Capacity: Computers have a very large storage capacity. The computers can store large amount of data and information, which is expressed in terms of kilobytes, megabytes and gigabytes in Moreover, the storage capacity of the computers can be increased by using secondary storage devices such as magnetic disk. The information stored in the secondary storage devices can be retrieved quickly with the help of main memory (RAM).
• Reliability: The computers give very accurate results with predetermined values. They correct and modify the parameters automatically and give suitable signals. They give formatted results with high degree of
• Versatility: Computers are very versatile machines with manual and automatic controls. They are capable of solving any problem and can be applied in all sorts of business and other
• Automation: The special feature of computer is automation, i.e., the computer executes a program continuously without any human intervention until completion. The central processing unit of the computer makes it processing unit of the computer makes it possible.

Limitations of Computer

The computer can outperform human beings in speed, memory and accuracy but still the computer has limitations. There are following limitations of a computer.

• Programmed by human: Though computer is programmed to work efficiently, fast and accurately but it is programmed by human beings to do Without a program, computer is nothing. A program is a set of instructions. Computer only follows these instructions. If the instructions are not accurate the working of computer will not accurate.
• Thinking: The computer cannot think itself. The concept of artificial intelligence shows that the computer can But still this concept is dependent on set of instructions provided by the human beings.
• Self-care: A computer cannot care itself like a human. A computer is dependent still to human beings for this
• Retrieval of memory: A computer can retrieve data very fast but this technique is linear. A human being’s mind does not follow this A human mind can think randomly which a computer machine cannot.
•  Feelings: One of the main limits in the computer is of feeling. A computer cannot feel about some like a human. A computer cannot meet human in respect of relations. Human can feel, think and caring but a computer machine itself cannot. A computer cannot take place of human because computer is always dependent of human.