An entity is a database object that has a graphical representation. Examples of entities include lines, circles, arcs, text, solids, regions, splines, and ellipses. The AcDbEntity class is derived from AcDbObject. For a complete class hierarchy diagram, see classmap.dwg in the ObjectARX classmap directory.
With a few exceptions, entities contain all necessary information about their geometry. A few entities contain other objects that hold their geometric information or attributes. Complex entities include the following:
Examples of creating and iterating through complex entities are provided in Complex Entities.