Paganism is a cover-all word for a whole raft of beliefs and life styles. It tends to cover a great deal of ancient belief systems - many Bronze/Iron Age European cultures i.e. Celts, Saxon, Norse, etc.
Best way to think of it is - Catholic, Methodist, Quaker - all different but all Christian.
I follow an ancient path, so that would make me a Primitive Pagan. Others in this forum, follow a modern path such as Wicca and are also pagan.