The Electronic Numerical Integrator and Computer, or ENIAC, was created under the direction of John Mauchly and J. Presper Eckert of Penn’s Moore School of Electrical Engineering (now the School of Engineering and Applied Science).
Construction of the 27-ton, 680-square-foot computer began in July 1943 and was announced to the public on Feb. 14, 1946. It was built to calculate ballistic trajectories for the Army during World War II, a time- and labor-intensive process that had previously been performed by teams of mathematicians working with mechanical calculators.
ENIAC stored information in the form of electrons trapped in vacuum tubes, making it the first all-electronic, general-purpose digital computer. The long string of adjectives distinguishes it from earlier mechanical computers, which were essentially gear-driven abacuses that could aid in complex math but could only calculate a small subset of equations.