Computer machine manipulated data that, in accordance with a list of commands.

The first devices that resemble modern computers day up in the middle of the 20th Century (1940-1945), although the computer concept and various machines such as computers existed earlier. Early computers were the size of a large room, consuming as much energy as several hundred modern personal computer (PC). Modern computers are small integrated circuits and the millions of billions of times more powerful, and the occupation of space. Today, simple computers may be small enough to get in an hour and is powered by the battery hours. Personal computers in various forms, are the symbols of the information age, and that is what most people think of as "computer", but the most common form of computer use is now embedded computer. Embedded computers are small, simple devices that are used to control other devices - for example, they can be found in machines from fighters of industrial robots, digital cameras and toys.

The ability to store and maintain lists of instructions, the program makes computers extremely versatile and distinguishes them from calculators. Church-Turing thesis of this mathematical universality: any computer with a minimum feature is basically the same tasks that any other computer can perform. For example, computers with the ability and the complexity of personal digital assistants supercomputers are capable of the same computer tasks enough time and memory.