Cosmology
There are three Umbra or Spirit Realms in the World of darkness. The Dark Umbra or land of the Dead, the Dream Umbra or Dreaming and the Spirit Umbra or true Umbra. When people say Umbra they usually mean the Spirit Umbra. This Umbra (in fact all three Umbra) is structured according to nearness or closeness to mundane Earth. However, this is more a matter of resemblance to Consensus reality than physical distance. The exception is Technological Videre where there is direct link between changing laws of surrounding conditions and distance from Earth surface.
Read more about this topic: Umbra (World Of Darkness)