Short for Electronic Numerical Integrator and Calculator, the ENIAC was the first electronic computer used for general purposes, such as solving numerical problems. It was invented by John Presper Eckert and John Mauchly at the University of Pennsylvania to calculate artillery firing tables for the United States Army's Ballistic Research Laboratory.
In 1953, the Burroughs Corporation built a 100-word magnetic-core memory, which was added to the ENIAC to provide it with memory capabilities. By 1956, the end of its operation, the ENIAC occupied about 1,800 square feet and consisted of almost 20,000 vacuum tubes, 1,500 relays, 10,000 capacitors, and 70,000 resistors. It also used 200 kilowatts of electricity, weighed over 30 tons, and cost about $487,000.
The picture is a public domain U.S. Army photo of the ENIAC. The wires, switches, and components are all part of the ENIAC with two of the team of operators helping run the machine. The ENIAC is now being displayed at the Smithsonian Institution in Washington D.C. In 1996, the U.S. Postal Services released a new stamp commemorating the 50th birthday of the ENIAC.