From time to time I am asked about the difference between shamanism and psychic ability.
While this is a topic that could fill many books, and there may be some overlap between the two, the short answer in reference to shamanism or shamanic practice is that it is a way of viewing all life that incorporates communication with the non-human world and making subtle energy changes in 3 planes non-ordinary reality.
Shamanic practitioners speak of journeying -- entering into a state of non-ordinary reality to speak with animal and plant spirits, find lost souls, and extract spiritual intrusions in one's energy fields.
A journey might be considered a kind of active clairvoyance in that the practitioner sees what others in normal consciousness cannot, and usually will gain knowledge or messages that are similar to what a clairvoyant psychic might receive.
Clairvoyance is the skill / talent of seeing what others don't see. It can be seeing events and motivations in the past, or possible event trajectories that might happen in the future, or seeing hidden forces / subtle energies of the present.
This is similar in structure to the three shamanic realms of the UpperWorld, MiddleWorld, and LowerWorld.
When I journey to interact with past events, I go to the LowerWorld. When I journey to view possible futures, I go to the UpperWorld. And when I journey to discern hidden forces acting in present time, it's usually to the MiddleWorld.
This is my own organization that may or may not be standard for other shamanic practitioners. It is what my animal guides have taught me.
Just as some clairvoyants have all three abilities -- seeing past, present, and future -- and some mostly see future, or present, or past, I imagine that there are shamanic practitioners who are more adept at journeying to one of the three worlds, than all of them.
I find it easiest right now to journey to the LowerWorld, and that coincides with my clairvoyant strengths in seeing the past lives. I have past life clairvoyance and present life claircognizance (clear knowing -- knowing without necessarily seeing images as the source of knowing).