Help translating It's not a bug, it's a feature!?

1. What does a feature not a bug mean?
2. When a bug becomes a feature?

What does a feature not a bug mean?

A feature is a functionality intended to be useful to the user. A bug is a behavior, usually the result of an error or sloppy programming, that gets in the way of the features.

When a bug becomes a feature?

When a bug really is a feature. Bugs, put simply, are errors or defects in a software system. If you work in tech, you've probably heard someone say the half-joke, half-truth line “it's not a bug, it's a feature”. Often this is used in jest or to justify not wanting to fix a particularly difficult bug.