A tribe is a very large collection of werewolves coming together to the point where they become a society. Much of werewolf society is organized into tribal groupings. A tribe will consist of a bunch of packs affiliated by blood or alliance. A tribe is basically the antithesis to the Brood which are a coven of vampires.
Tribes do not usually live together, but do gather periodically to reaffirm bonds and discuss and rule on important issues. Each tribe, in one form or another, is nominally ruled over by council of elders made up of the most powerful pack leaders and pack mothers within the tribe.
However, despite the fact that a tribe is formed through the affiliation of blood or alliance, a werewolf is not bound to join the tribe of their ancestry; a cub, for example, may not meet the standards expected of a tribe and is therefore unacceptable as a member. The personal philosophies of an individual werewolf may also drive them to seek another tribe that meshes better with their views. Some tribes specialize in taking in cubs who were rejected by their ancestral tribes.
Despite the seemingly pacifistic nature of a tribe due to its spiritualism, it possesses a series of harsh trials for any lycan that wishes to become a fully fledged member of the tribe. In order to become a full-fledged member of any tribe, ancestral or not, a werewolf must pass a Rite of Passage, in which the elder of the tribe accepts them once they prove their worth of being a true lycanthrope and in their words "have your soul be bound to the moon, your flesh with the Earth, and your being with the animal kingdom."