The first devices that resemble modern computers date to the mid20th century
(around 1940 1945), although the computer concept and various machines similar
to computers existed earlier. Early electronic computers were the size of a
large room, consuming as much power as several hundred modern personal
computers. Modern computers are based on tiny integrated circuits and are
millions to billions of times more capable while occupying a fraction of the
space. Today, simple computers may be made small enough to fit into a wristwatch
and be powered from a watch battery. Personal computers, in various forms, are
icons of the Information Age and are what most people