From Pluralpedia, the collaborative plurality dictionary
realm (n., adj.)
Applies toheadspaces, system functions

Realms are separate areas of the innerworld that may or may not be part of the main headspace of the system.

They can be connected by gates, and can sometimes be an inbetween of systems, both internal and external systems. It can be like a room or hallway inbetween two other rooms.

Traveling to them may be complex or simple, and it depends on each system how they access them.