A shaman in tribal societies of Northern Eurasia is a person who can communicate with the spirit world in order to make the spirits help people in desired ways: healing, fortune telling, enchanting amulets etc. A shaman is supposed to enter an altered consciousness state to do this. For that they can take certain mushrooms or other substances, meditate, make hypnotizing music and dances and so on. In short, a shaman in a shamanistic belief system is like a priest in a religious system.