Whats the difference between werewolves and shapeshifters?

Okay, werewolves are 'The Children of the Moon'. The ones that Caius hunted and almost got defeated by. The ones who change during full moon and all that stuff. Shapeshifters are people like Jacob, Sam,...the pack. Shapeshifters developed because the vampires (bad ones) were near, and they were enemies with them because they brought danger to the area. In New Moon, when Bella goes with Jacob to the campfire, they tell stories about this.