The first digital computer and what most people think of as a computer was called the ENIAC. It was built during World War II (1943-1946) and was designed to help automate the calculations being done by human computers. By doing these calculations on a computer, they could achieve results much faster and with fewer errors. Early computers like the ENIAC used vacuum tubes and were large (sometimes room size) and only found in businesses, universities, or governments. Later, computers began utilizing transistors and smaller and cheaper parts that allowed the ordinary person to own a computer.