A computer is a device which accepts input data, processes it according to programmed rules, calculates results and then store and or output those results.
Types of computers
Computers can be classified as follows.
2 Mainframe computers
4 Microcomputers now we called it as PCs
A supercomputer is used to process very large amounts of data very quickly. They are particularly useful for occasions where high volumes of calculations need to be performed, for example in meteorological or astronomical applications.
A mainframe computer system uses a powerful central computer, linked by cable or telecommunications to terminals. A mainframe has many times more processing power than a PC and offers extensive data storage facilities.
Mainframes are used by organizations such as banks that have very large volumes of processing to perform and have special security needs, many organizations have now replaced their ol mainframes with networked “client server’ systems of midrange computers and PCs because this approach is thought to be more flexibility.
A minicomputer is a computer whose size, speed and capabilities lie somewhere between those of a mainframe and a PC, the term was originally used before PCs were developed, to describe computers which were cheaper but less well equipped than mainframe computers.
With the advent of PCs and of mainframes that are much smaller than in the past, the definition of a minicomputer has become rather vague. There is really no definition which distinguishes adequately between a PC and a minicomputer.
PCs are now the norm for small to medium sized business computing and for home computing, and most larger business now use them for day to day needs such as word processing, often they are linked together in a network to enable sharing of information between users.