the dictionary explains it as the passing use that regulates, depending on the likes of that moment, the way we dress up, live, etc…
I definitely agree with this, even though I think fashion is more than just that; people express themselves by means of fashion. The way someone dresses, lives or acts, can tell you a lot about them and I’m sure that’s the main reason why we normally judge people at first, only by their appearance and most of the time this causes us to have a wrong opinion about someone.