Those who have been cursed or bitten by another creature are called Beta werewolves. They have little or no control over their changes from Man to Wolf and Wolf to Man, and are subject to phases of the Moon.
Some legends suggest that Betas have no free will at all, but most suggest that they are just spiritually bound in servitude to the Alpha. Also, Betas are made to mate with the male or female Alpha.
The relationship between Alpha and Beta werewolves is a complex one. Once a subject is bitten by a werewolf, his or her life and death are doomed to the werewolf curse. The victim does, however, have some hope - as long as they themselves do not taste of human blood, the curse is reversible.
If the Alpha werewolf is killed - through some action of the Beta - the Beta's curse is broken. It is important to note that whether the Beta werewolf was bitten by the Alpha werewolf himself or by another Beta, it is the Alpha who must be destroyed - the source of the original tainted blood.
It is also an interesting note that since Betas and Alphas share common blood, an Alpha cannot physically harm a Beta of his own bloodline by his own hans without inflicting the same injury upon himself. However, if a Beta is harmed or killed by another, it does not affect the Alpha.
Omega Werewolves are those created in the same fashion as the Beta, but were cursed by a Beta and not the Alpha himself. The Omega Werewolves are considered as the lowest level in a pack.
Note that this classification is modern and has no historical or cultural background to support it.