Multiverse

The multiverse (or meta-universe) is the collective set of all universes in existence. Together, these universes comprise everything that exists: the entirety of space, time, matter, energy, and the physical laws and constants that describe them.

The various universes within the multiverse are called "parallel universes", "realms", "dimentions", "other universes", or "alternative universes".

History
In Dublin in 1952, Erwin Schrödinger gave a lecture in which he jocularly warned his audience that what he was about to say might "seem lunatic". He said that, when his Nobel equations seemed to describe several different histories, these were "not alternatives, but all really happen simultaneously". This is the earliest known reference to the multiverse outside of fiction

List of known dimensions

 * Dream Dimension
 * Dark Dimension
 * Sacred Realm
 * Termina Realm
 * Lorule Realm
 * Twilight Realm
 * Celestial Realm
 * Underworld Dimension
 * Subspace Dimension