Not sure what it does.
WineTricks is used alongside Wine to get files that are needed for whatever app/game you are trying to get to run.. Ok.. not exactly user friendly, at first.. For example.. if you need to get a DLL/font/run winecfg/etc..., you hit OK after you open it (the radio button will be on "Select the default wineprefix") from there, you will get more options.. (and is a bit easier to understand where to go for what you need to do).