The DRM is Composed of ...
Geometry: type objects Physical/surface representations of real world objects (is: 3D polygons, patches, lines, and points)
Feature: type objects Represent higher level abstraction of real world objects (ie: areal, linear, and point features)
Topology: Concise, mathematical definition of inter-Feature or inter-Geometry object relationships
Attributes: (ie: location, time, color, sound, width, etc.)
Libraries: Store copies of any instanceable object
Explicit relationships Among feature objects, geometry objects, or between feature and geometry objects
Organizational schemes Allows for well-described hierarchical configuration of geometry and feature objects