Organisms living in close association often to the benefit of both is called?

An interaction in which one organism lives in a close association with another is called symbiOSis. There are three types of symbiOSis; mutualism, parasitism, and commensalism. In mutualism, both species benefit from the association; in parasitism, one species benefits at the expense of the other; and in commensalism, one species benefits and the other species is neither harmed or helped.