Prime Material Plane
The Prime Material Plane is the plane of existence in which Acaelica, the surrounding cosmos, and all Parallel Planes can be found. It is often simply referred to as the Prime.
This plane is the nexus where philosophical concepts and elemental forces collide in a jumbled mess of mortal life and matter. Not unexpectedly, the rest of the multiverse is always defined in relation to the Prime.
Worlds of the Prime are infinitely diverse. All the "mortal worlds" of the multiverse exist within this plane, among them Abeir-Toril, Oerth, Krynn, Athas, Eberron, and even the universe in which Earth is located. You know... This one! I know!