Human race has realized the need for a tool to work with numbers a few centuries ago and invented rudimentary tools to meet this growing need. Over the centuries such tools evolved into the present day computers.
The computer is an idiot box because it has no brain by itself. It has no innate skills as a human being. It has to be instructed sequentially the mathematical and logical steps involved in solving the problem in which we are interested.
Computer is an electronic device which works on the data and gives the result. Computer can perform calculations on data and can give output. It can also do the logical comparison on data.
Computers are used in various commercial applications like, accounting, personnel, sales analysis, stock orders, inventory management, banking, airlines, libraries and manufacturing etc.
Generations of computers:
These computers were used in the period between 1951 to 1959. These computers were made with vacuum tubes. These were very large in size and very slow in working.
These computers were used in the period between 1959 to 1963. Transistors were used In the place of Vacuum tubes. These were much reliable and faster in speed and smaller in size when compared to the 1st generation of computers.
3rd generation :
These computers were used in the period between 1963 and 1975. Integrated circuits were used in the place of transistors. Integrated circuit means combination of many transistors and an electronic circuit in a single chip. These were much reliable, faster in speed and were more capable to store data, when compared to 2nd generation computers.
These computers are in use since 1975. These are made of micro processor chips,
Which hold the entire control unit and arithmetic and logic unit.
Elements of a computer:
A computer consists of three major elements. They are
Hardware refers to the physical components of a computer. The major hardware
Component of a computer is memory.
Software is the set of instructions that guides the hardware through its job. Based on the Functions of the software, it is divided into two categories. They are
Computers need system software to function properly. Operating system is a well- Known example for system software. ( example: DOS, Windows, Linux, Mac OS)
Application software directs the computer to do the specific task. Examples are printing Records and maintaining data bases.
Computers transform data into information. Data is a raw material and information is a processed data. i.e. data is input and information is output.