Please explain what a "slug" is

Related to teams you use the term "slug". I'm a non-native English speaker, have no explicit IT education, and only know the nice little slimy animals with this name - so first off I was absolutely clueless what this is about. By now I assume it's the "short name" of teams, like the user login name on Linux systems.

E.g. somewhere I read about writing to "team+slug@t.d.o". Maybe I could understand it, if I'd ever seen the "slug" of a team. But first I didn't know if this means foo+slug@t.d.o or team+foo@t.d.o.

I could only find a little, but not really helpful explanation here:

https://tracker.debian.org/teams/+create/ "Slug" - "A team's slug determines its URL"

Thanks again jre