A computer is a machine capable of processing data according to a program — a list of instructions. The data to be processed may possibly represent many types of information counting numbers, text, pictures, or sound. The short definition for COMPUTER is “common oriented machine particularly used for technical and educational research”.
Computers can be very versatile. In actual fact, they are universal information processing machines. As said by the Church-Turing thesis, a computer with a certain minimum threshold capability is in principle competent of performing the tasks of any other computer, from those of a personal digital supporter to a supercomputer. So, the same computer designs have been modified for tasks from processing company payrolls to controlling industrial robots. Modern electronic computers also have great speed and capability for information processing compared to earlier designs, and they have become exponentially very powerful over the years (it is a phenomenon known as Moore's Law).
Computers are obtainable in many physical forms. The original computers were the size of a large room, and such great computing facilities still exist for specialized scientific computation - supercomputers - and for the business deal processing requirements of large companies, in general called mainframes. Smaller computers for personage use, called personal computers, and their handy equivalent, the notebook computer, are ubiquitous information-processing and communication tools and are perhaps what most non-experts imagine of as "a computer". However, the most ordinary form of computer in use today is the embedded computer, small computers used to manage another device. The Embedded computers control machines from the fighter planes to digital cameras.