Bottles is essentially a frontend for Wine, it lets you put every single app to its own WINEPREFIX, so that each one can have their own settings, C: drive, etc.
If you've heard of Lutris, Bottles is essentially the same thing, but aimed at general software instead of only focusing on games
Well, things have to be named something. At least "Bottles" are related to "Wine" in a way that makes sense for a name for isolated Wine environments. It is also unique enough that Google will give you the answer quickly.