In religion, visions comprise inspirational renderings, generally of a future state, and may come from a deity, directly or via prophets, and serve to inspire or prod believers as part of a revelation or an epiphany.
Artistic inspiration may provide a special category of the ecstatic vision: traditionally in such cases the semi-divine Muses may transmit the visioning to their loyal followers.
Visions generally have more clarity than dreams, but traditionally fewer psychological connotations.
Certain hallucinogenic techniquess can traditionally assist in the divine-to-human communication of visions, and may also allegedly generate visions.