Brainteaser: what does this tag mean?

The tag looks like it's heading for being our catch-all tag here.

I don't really understand what “brainteaser” means. It's not that far from being a synonym of “puzzle”.

A brain teaser is a form of puzzle that requires thought to solve. [Wikipedia]

a problem for which it is hard to find the answer, especially one which people enjoy trying to solve as a game [Cambridge)

Should we have this tag at all? If so, what should it mean — what types of puzzles do and do not qualify, and when should questions get that tag? Once we get a consensus, this needs to be clearly explained in the tag wiki.

• I'd say the sliding bolt puzzle is mostly logic, while the other two are mainly maths puzzles. So maybe we should have a tag like math-puzzle or numeric-puzzle? – DisgruntledGoat May 20 '14 at 22:23