There are many different variantions of "shamans" known. From the Ka-Huna of Hawaii, healers of the Hmong, the Sangoma of the Zulu, the healers of the Aborigines and Papua New guinea, the Sami healers, the shamans of Manchuria and Siberia, the medicine-men of North America and the healers of the Amazon .. all have 1 thing in common ...
They heal with herbs & energy, guide thier communities, protect the communities from spirits and negative energies, and they the spiritual law-keepers and storytellers that teach the ethics and ways of life for the people to stay in balance with nature.
One main thing to note is that shamans reach beyond the ordinary world -- and travel thru the spirit realms in order to deal with spirits, dis-ease and knowledge gotten beyond mere logic -- thus -- shamans deal with spirits and the spirit-realms on a daily basis. The Shaman is a mediator -- thus, when the ancestor spirits must be spoken with due to a person breaking a taboo, offerings are given, the shaman travels into the spirit-realms and discusses the persons appropriate punishment for breaking that taboo -- so thus, the shaman is a spiritual law-keeper and mediator between the people and the spirits. Another aspect that shamans do is called a psychopomp -- thus when a person dies and cannot join the ancestors (thru terrible acts, such as murder, rape, suicide, and so on -- are forced to walk amongst the living as ghosts) and so the Shaman talks with the unhappy wandering ghost and is a mediator for the spirit in getting them to be able to join the ancestors. Also, using herbs or energy means, the shamans are a vessel for a person to be healed, no matter if a simple headache is gotten rid of -- to a persons soul is shattered and needing to be re-integrated again. The shamans also being teachers watch over the children, and closely examine the kids -- as the shamans see which ones are interested in spirits and the spirit-world, as shamans then closely teach that 1 child -- as the tru ways are a strong, close 1-on-1 teaching method, instead of the newagey form of "classes" and "workshops" that modern "plastic-shamans" try to pull. Also the shaman is closely aware of nature around them, looking at everything -- a wisp of wind, an animal going in a direction -- or even a totem speaking up -- the shaman sees omens, messages and warnings on a daily basis no matter if out for a walk -- or in thier dreams -- all of these are held in serious regard.
So then the saying of "There is only 1 shaman per village" is apt, as the calling, burden and responsibility of being one -- one can see why there are so few true spirit-called shamans and that is a thing to be taken serously.
So we see the shaman wearing many hats -- a law-keeper, a counselor, mediator, guide, protector, excorcist, healer, teacher and mentor. It takes years and years of training -- emotional and spiritual development -- and lots of life experiences added in ..:)