The term "computer bug" originated on September 9, 1947, when a team at Harvard found a literal moth trapped in the hardware of the Mark II computer, causing errors.
Although the term "bug" had been used by Thomas Edison to describe flaws in his designs, this was the first time it was applied to a computer. Dr. Grace Hopper, a member of the team, helped popularize the term, which is now widely used to describe flaws or glitches in computer systems.