The Planes of existence are often referred to as the spheres, they are the physical manifestations of the great celestials and their might, they forged that which all mortal and immortal life now exists upon. Carved from the bones and entrails of their foes did they shape the world as to the vision of Raziel. The planes are often to as the greater spheres and the lesser realms to distinguish between the smaller planes which reside within the greater planes the smaller planes which orbit or float within the astral sea. The Four greater planes are the central spheres of life, with four of the great spheres having been specifically made to sustain life on material planes, each of them overlaps the material plane and most of them contain what one could also refer to as a plane of existence, the distinction between realm and plane merely being that the realms sustain life upon a plane. Though it is not sure if there was ever intended to be living in these realms, most of them are now inhabited a wide series of creatures.