Back in the '70s the "Hook" was the place in the song where Donna Sommer faked an orgasm.

A hook is actually a cheap device upon which a song lyric is based. An example might be:

Oooh baby, luv ta luv ya
Luv ta luv ya yeah!

The title of the song would then be Ooooh Baby, Luv Ta Luv Ya. This is not really considered a sophisticated device by yours truly
Jim