For me/us/we/the company I work for - a bug is something that be tracked, logged, and reproduced and can get, well, "squashed."Coming from a programming perspective, I'm not sure anyone could define to you the difference between a glitch and a bug.
Edit: https://en.wikipedia.org/wiki/Glitch It's kind of funny reading Wikipedia's page on it, it gives some vague difference in definition, but the Video Game section immediately writes about "glitches/bugs" and uses them interchangeably a few times.
"it's not a bug, it's a feature" is something you hear/read
A glitch would be something like a tempory disruption, or a one-off, unreproducible, even an unintended side-effect