The ENIAC (Electronic Numerical Integrator and Computer) was the world's first programmable, general-purpose electronic digital computer, commissioned by the U.S. Army during World War II. Officially unveiled at the University of Pennsylvania on February 15, 1946, it cost roughly $487,000 at the time (nearly $7 million today). While it was originally built to automate military calculations, its massive scale and support system birthed the exact operational principles used in modern data centers.