Shamanism is both easier to spell and easier to pronounce.
That’s a good question, actually, but it’s a fairly simple answer. Animism is a belief structure that says that everything has a spirit. Shamanism is closer to a religion, in that it has set structures and rituals, as well as fixed beliefs and consequences. Also, Shamanism believes in the ritual death and rebirth of the Shaman. Without this spiritual death and rebirth, the individual could never be a Shaman.
neither of them are capital-letter religions. animism is the belief that spirit permeates all life, and for some, all matter. shamanism describes most indigenous tribal religious, spiritual, or mystical traditions and involves a system of beliefs and practices related to the culture of each culture. the term is siberian or indigenous russian in origin and has come to refer to any aboriginal magical practice.