Many people use the term 12 bar blues to refer to the structure / chord progression commonly used in most blues (the clue is in the name!) and also jazz, some rock songs as well.
Sometimes it's abbreviated to just "blues", but either way I don't quite like the way the term is used. Gives the wrong impression about the whole music form and people assume that all blues is just anything with 12 bars.
Ok, end of rant. :lol: