Since we cannot simply view the totality of world from the outside, we can only speculate about what planes (or realms) actually are. The consensus is that a plane is a state, level, or region of actual or virtual reality, corresponding to some category of being or non-being, and confined by the membrane of the Liminal Plane, which tunnels serve as boundaries separating the plane from other planes. It is assumed, that each plane has its unique properties and that there are infinite amount of planes. Navigating the planes is a non-trivial task, that usually requires a lot of skill and resources, or an inherent affinity to this plane (like draoithe and the Nature's Realm).