The humble microchip can be considered one of the greatest inventions of the 20th Century. It allowed electrical devices requiring some form of intelligent control to be shrunk down in size rather than using large, clunky relays. Over the course of time, computers have gotten ever more powerful while reducing in size. Generally speaking, the main limitation to a computers size was the heat being produced and thus alot of space was taken up by heatsinks. Today we see the humble slivers of silicon being extremely powerful but also very efficient giving off less heat. This has allowed manufacturers to decrease the size of components that once took up a large room down to something that comfortably fits in your pocket.