Final answer:
Mark-1 is known as the giant computer because of its large physical size. It was a pioneering machine developed at Harvard University in the 1940s.
Step-by-step explanation:
Mark-1 is known as the giant computer because it had a large physical size. The Mark-1 computer, also known as the Automatic Sequence Controlled Calculator (ASCC), was developed at Harvard University in the 1940s. It was a massive machine that filled an entire room and consisted of rotating shafts, gears, and mechanical switches. Although it could perform complex calculations, it was primarily known for its size and the pioneering role it played in the early days of computing.