Wikipedia - Shamanism
Shamanism is a practice that involves a practitioner reaching altered states of consciousness in order to perceive and interact with what they believe to be a spirit world and channel these transcendental energies into this world.
A shaman (/ˈʃɑːmən/ SHAH-men) is someone who is regarded as having access to, and influence in, the world of benevolent and malevolent spirits, who typically enters into a trance state during a ritual, and practices divination and healing. The word "shaman" probably originates from the Tungusic Evenki language of North Asia. According to ethnolinguist Juha Janhunen, "the word is attested in all of the Tungusic idioms" such as Negidal, Lamut, Udehe/Orochi, Nanai, Ilcha, Orok, Manchu and Ulcha, and "nothing seems to contradict the assumption that the meaning 'shaman' also derives from Proto-Tungusic" and may have roots that extend back in time at least two millennia. The term was introduced to the west after Russian forces conquered the shamanistic Khanate of Kazan in 1552.
The term "shamanism" was first applied by Western anthropologists as outside observers of the ancient religion of the Turks and Mongols, as well as those of the neighbouring Tungusic and Samoyedic-speaking peoples. Upon observing more religious traditions across the world, some Western anthropologists began to also use the term in a very broad sense. The term was used to describe unrelated magico-religious practices found within the ethnic religions of other parts of Asia, Africa, Australasia and even completely unrelated parts of the Americas, as they believed these practices to be similar to one another.
Mircea Eliade writes, "A first definition of this complex phenomenon, and perhaps the least hazardous, will be: shamanism = 'technique of religious ecstasy'." Shamanism encompasses the premise that shamans are intermediaries or messengers between the human world and the spirit worlds. Shamans are said to treat ailments/illness by mending the soul. Alleviating traumas affecting the soul/spirit restores the physical body of the individual to balance and wholeness. The shaman also enters supernatural realms or dimensions to obtain solutions to problems afflicting the community. Shamans may visit other worlds/dimensions to bring guidance to misguided souls and to ameliorate illnesses of the human soul caused by foreign elements. The shaman operates primarily within the spiritual world, which in turn affects the human world. The restoration of balance results in the elimination of the ailment.