Charles Babbage invented the first mechanical computer, called the Difference Engine, in 1821 and completed it in 1832. The Difference Engine could perform simple calculations and compile mathematical tables. Babbage later conceived the Analytical Engine, a device that could perform any calculation, but was unable to construct a prototype during his lifetime.
Charles Babbage's ideas were revolutionary for his time, but manufacturing capabilities at the time held him back. The next major breakthrough in computing occurred years later, in 1936, when Alan Turing introduced the idea of the modern programmable computer. This led to electromechanical computers in the late 1930s, devices that used electric switches and mechanical relays to work. They were soon replaced by all-electronic computers that first used vacuum tubes, but progressed to the use of transistors and then integrated circuits in the 1950s.