From the White Wolf Wiki, the most complete White Wolf reference

The Realms Supernal are probably best describes as might-have-been realities, dimensions in which a certain aspect of magic reigns supreme. Each Realm Supernal focuses on a certain aspect of a higher reality where the Awakened alone determines what is real and what isn't. The five Realms accessible to modern mages are these:

Arcadia

In the realm of Arcadia, anything is possible. Time and fate are just as tangible and navigable as height and distance, and promises and wishes are law.

Pandaemonium

In Pandaemonium, distance and space are meaningless, and all ideas may be learned and experienced. There is no escape, neither from yourself and your sins, nor from others.

Stygia

Stygia is the realm of death and inanimate things. Everything comes to an end here, and everything that has ended and become static can be transmuted into a new form. This is the place where even Death may die.

The Aether

This is the realm of energy, both physical and mystical, a place of raw power that can be shaped into any form for higher purposes.

The Primal Wild

Life in all its physical and spiritual forms rules this realm. There is nothing here that isn't alive after some fashion.

Source: Mage: The Awakening core rule book