when was the first computer invented

The idea of a “first computer” depends on what you count as a computer, but there are a few widely cited milestones:

• The ancient Antikythera mechanism, built around 100 BCE, is often called the earliest known mechanical analog computer because it calculated astronomical positions.

• In 1822, Charles Babbage proposed the Difference Engine, an automatic mechanical calculator, and later designed the Analytical Engine, which many historians see as the first design that truly resembles a modern general-purpose computer, though it was never completed in his lifetime.

• In the late 1930s and early 1940s, electronic and electromechanical machines appeared: the Atanasoff–Berry Computer (ABC, developed 1937–1942) is often recognized in court rulings as the first electronic digital computer, while Konrad Zuse’s Z1 (1936–1938) is considered the first electromechanical binary programmable computer.

• Colossus (first demonstrated 1943) and ENIAC (1945) are among the first large-scale electronic digital computers; ENIAC is often popularly cited as “the first computer” even though that simplifies a much more complex history.

Because historians use different criteria—mechanical vs. electronic, analog vs. digital, programmable vs. special‑purpose—there is no single agreed‑upon date when “the first computer” was invented.

If you had to pick just one angle (for example, “first electronic digital computer” vs. “first computer design in history”), which version are you most interested in?