The Aether (Earth's Magic World)
Ours (Earth, Milky Way Galaxy, etc), AU (Alternate Universe)
The Aether is an artificial dimensional plane anchored to the planet Earth. It was created when, far in the past, magic forces and those things affected by them were separated from Earth altogether, and put onto another plane.
However, the Aether's connection to Earth was unstable. Thanks to 'breaks' in time between the Aether and Earth (where the Aether spent uncounted years as a free-floating dimensional plane, with time moving incredibly fast in comparison to its parent dimension), in the present the Aether has long evolved and expanded out of all control of its original creators - wherever they are now.
The Aether is, simply put, the magic world of Earth.