Backgrounds are points that help flesh out a character for roleplay and assign a relative power-level to useful, in-game 'background' parts of the character. Most of them should be described in your &GMINFO to aid GMs in making use of them.
It is important to note that you don't need to spend Background points on things which will never have an impact IC, but rather for things which will actually be relevant in current gameplay and can be used in plots and scenes, or to +learn/teach. As an example, you don't need to spend Kinfolk or Allies points on a Garou's parents unless you'd like those parents to provide a resource or exert an influence. It's understood everyone has or had parents; characters aren't expected to spend points for them to exist. On the other hand, not everyone has parents who come onto the game and help them out of a bind (Allies).
The following Backgrounds are available for characters on GarouMUSH. Please note that not all Backgrounds are available to all character types. On the MUSH, you can access information via +info/bg <background>.