When software fails we are often told: “It’s a bug.”

We have Grace Hopper to thank for that expression.

Hopper was a computer scientist and United States Navy rear admiral. She was one of the first programmers of the Harvard Mark I computer and one of the leading early figures of computer science.

Hopper, who died in 1992, led an amazing life. These days she is also well known for having a major series of conferences named after her: The Grace Hopper Celebration of Women in Computing.

Hopper is also credited with popularizing the word “bug” and “debugging” to describe glitches in software.

It happened while she was working on a Mark II computer at Harvard in 1947. Her colleagues discovered a moth stuck inside the machine.

The word “bug” had been used for decades to describe malfunctions in other fields. Hopper’s team had the humor to tape to the moth to their daily log sheet and write: “First actual case of bug being found.”

And thus begun the tradition of describing computer and software glitches as “bugs” and fixing them as “debugging.”

The log page is now housed at the Smithsonian museum in Washington.