A computer is an invention of modern science that uses technology to manipulate the data according to the instructions received. The beginning of this modern piece of gadget goes back to the mid 20th century, though the concept of computer existed even earlier. The early computer was of the size of an immense room, and consumed the power equivalent to several modern personal computers. 

With the growth in the VLSI sector, tiny integrated circuits were introduced which are about a million times more capable than their earlier counterparts while acquiring a minimal space. The computer of the modern century is small enough even to fit in a hand held gadget such as a PDA or even a wrist watch and works with a small battery. The most common form of the available computers is embedded computers. These are simple and small devices and are used to control other devices of daily use. They are found in various machines varying from children’s games to aircrafts. The world today depends on these gizmos.

The lists of instructions which are stored to be executed in any given time are called programs. This makes the computers very versatile and hence distinguishes them from calculators. According to the church turing thesis, any computer with a certain capability is, according to principle capable to perform the same tasks as any other computer available. The complexities of the computers are quite variable varying from PDAs to a supercomputer and they all can perform the same tasks of computation when given enough storage capacity and the time of operation