Zone

Zone is the Mobian term for other dimensions and universes besides the Prime Zone. Travel between these worlds, while uncommon, have become possible through various means, such as the Genesis Portals

The term Zone can also refer to various areas on Sonic's World] itself, such as the Green Hill Zone.

Dimensions
The Magic Dimension encompasses every realm dimension pocket zone and alternate zone in Sonic's Multiverse it is also refered to as The Magic Universe as well as The World of Magic

An alternate zone is a parallel universe with the same physical properties as Prime Zone, but with a different history. Alternate zones can be very similar to Prime Zone (such as Moebius,which seemingly has a counterpart of every resident of the Prime Zone) or quite different (like Sol Zone, which is populated by Mobians, but none of them appear to be counterparts of anyone from Prime Zone.)

Alternate Reality Zones
Named Alternate Zones
 * Prime Zone
 * Zone-16
 * Moebius Zone
 * Earth Sonic's World
 * Zone EGG
 * Zone Underground
 * Boom Zone
 * Cop Zone
 * Regal Academy Universe