A computer is a machine that manipulates data according to a set of instructions.
The Columbia Supercomputer, located at the NASA Ames Research Center.
Although mechanical examples of computers have existed through much of recorded
human history, the first electronic computers were developed in the mid-20th century
(1940–1945). These were the size of a large room, consuming as much power as
several hundred modern personal computers (PCs). Modern computers based on
integrated circuits are millions to billions of times more capable than the early
machines, and occupy a fraction of the space.Simple computers are small enough to
fit into a wristwatch, and can be powered by a watch battery. Personal computers in
their various forms are icons of the Information Age and are what most people think
of as "computers". The embedded computers found in many devices from MP3
players to fighter aircraft and from toys to industrial robots are however the most
numerous.