The Dream Realm is the main connection between the numerous universes and dimensions that reside within the greater Fantendo Multiverse. It contains portals to every location in the multiverse, possibly even portals to other multiverses, that can be accessed from within the Dream Realm by it's inhabitents and deities. Mortals brought to the Dream Realm are able to use the portals, though are not usually able to reopen a portal to the Dream Realm once leaving.
These beings naturally inhabit the Dream Realm, and are able to travel to and from it, at will.
These beings, much like inhabitents of the Dream Realm, are able to open a portal to the Dream Realm at will.