Multiverse

The Multiverse refers to the multitude of alternate realities and dimensions that exist in conjunction with that of Sonic the Hedgehog.

Before Worlds Collide
The Multiverse previously consisted of multiple Zones linked to each other by the Cosmic Interstate and patrolled by the Zone Cops.

After Worlds Collide
The interrupted reversal of the Super Genesis Wave caused the multiverse associated with Sonic's World to collapse. This resulted in the creation of Genesis Portals that linked various dimensions together.