The DRM is Composed of ...
Geometry type objects Physical/surface representations of real world objects (e.g., 3D polygons, patches, lines, & points)
Feature type objects Represent higher level abstraction of real world objects (e.g., areal, linear, and point features)
Topology Concise, mathematical definition of inter-Feature or inter-Geometry object relationships
Attributes (e.g., 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