Short answers, pulled from the story.
The Modern English word shamanism derives from the Russian word shamán, which itself comes from a Tungusic language. This root likely originates from the southwestern dialect of the Evenki spoken by the Sym Evenki peoples or perhaps from the Manchu language.
Dutch statesman Nicolaes Witsen brought the concept to Western Europe twenty years after 1672 in his book Noord en Oost Tataryen published in 1692. Adam Brand introduced the word shaman to English speakers in 1698 through a translation of his account of a Russian embassy to China.
Anthropologist Manvir Singh argues that the most justifiable definition includes three basic features: entering non-ordinary states, engaging with unseen realities, and providing services like healing and divination. The Oxford English Dictionary defines a shaman as someone regarded as having access to and influence in the world of benevolent and malevolent spirits.
In November 2008 researchers from the Hebrew University of Jerusalem announced the discovery of a 12,000-year-old site in Israel perceived as one of the earliest-known shaman burials. This grave contained an elderly woman arranged on her side with legs apart and folded inward at the knee surrounded by stones and animal remains.
According to Michael Winkelman trance states induced by dancing hallucinogens and other triggers have an integrative effect on cognition. Methods employed include autohypnosis entheogens or ritual performances such as using a drum made of animal-skin stretched over a bent wooden hoop with a handle across the hoop.