What is the difference between Wicca and Pagan?

Paganism is an umbrella term for a variety of religious beliefs, including Shamanism, Asatru, Witchcraft, Stregha etc.. Wicca is one of those.

Pagans generally believe on the forces of nature and individual power and individual being a part of the collective life force of the 'Earth'.

Pagan religions are not organized hierarchal religions. The only hierarchal structure in pagan groups the leadership of the more experienced adepts to the newbies joining that group. Pagan religions are actively practiced by the followers and there is no distinction between followers and priests as such. There is no authoritative organism above all the groups of a pagan religion.

Though there are similarities between many pagan paths and traditions, each pagan religion has its own lore, roots, history and core beliefs that distinguish between them. Even among Wiccan covens (groups of practitioners) there are slight differences of their lore and techniques of practice