Definition of a Shifter:
In contrast, Shifters are a relatively new concept. The idea of a shapeshifter wolf has been around for a moderately long time, but the rules and lore of it all mostly came in a spike after the publication and popularity of Twilight. I might add that Stephanie Meyers admits in the last book that these Shifters are not werewolves any more than Edward Cullen is.
Shifters can control their transformations, though some people still say that they have an urge to shift on the full moon. This, however, might come from the fact that wolves love to be social on full moons. Instead of the conglomeration "monster" image that werewolves take in their transformations, Shifters are either full human or full wolves. Their wolf aspects may be the size of normal Canis lupus, or they may be a big bigger. Shifters are completely aware of their actions as wolves, and actually sometimes continue to act like humans while they're wolves. Sometimes, however, they have a sort of "wolf subconscious" (a mixture of wolf instincts and subconscious thoughts) that takes over while they're in wolf form. And then, the human becomes more of a subconscious to the wolf, though the two still work mostly as partners. Because wolves and humans are some of the most social species there are, Shifters are often depicted as having some sort of "Pack" that is mug larger than a wolf pack, but slightly smaller and more close knit than a a human social group. Like with wolves, this pack is a mixture of friends, family, and friends of family.