This article is from the Religion-Shamanism FAQ, by Dean Edwards, Stef Jones, Jilara, Jane Beckman, Ann Albers with numerous contributions by others.
In the Harner Method of shamanic journeying,
this is where the person journeys to during a session. These
alternate realities are described as a higher, middle and lower
world. Non-ordinary realities parallel the existence of this world.
Dean Edwards (email@example.com)