Once upon a time, there were six clans of cats: StarClan(don't own this clan), LifeClan, IceClan, DarkClan, FireClan, and SunClan. Each clan has teir own leader, deputy and medicine cat. Also, each clan has its own laws. For example, Darkclan doesn't go to Fourtrees (I don't own this either) for gatherings, StarClan has many laws, SunClan usually shows up at gatherings, and so on.
  FireClan cats have short pelts bcuz their territory is always sunny (it has green grass, fyi), and IceClan cats have long pelts bcuz their territory is always cold. LifeClan isn't supposed to be a clan, but since DarkClan doesn't go to any gatherings, there is an empty tree with LifeClan's name on it.