3D's superstructure consists of one or more VirtualUniverse objects, each of which contains a set of one or more high-resolution Locale objects. 3D defines the concept of a virtual universe as a three-dimensional space with an associated set of objects. Virtual universes serve as the largest unit of aggregate representation, and can also be thought of as databases.
Virtual universes can be very large, both in physical space units and in content.
Indeed, in most cases a single virtual universe will serve an application's entire needs. Virtual universes are separate entities in that no node object may exist in more than one virtual universe at any one time. Likewise, the objects in one virtual universe are not visible in, nor do they interact with objects in, any other virtual universe. 3D introduces the concept of Locales that have high-resolution coordinates as an origin. A Locale, with its associated high-resolution coordinates, serves as the next level of representation down from a virtual universe.