Concrete class

A concrete class can have instances stored in the database. In contrast, an abstract class cannot have any instances.

A selection on the Class form determines whether a class is concrete or abstract.

Concrete classes usually appear near or at the bottom (leaf nodes) of the class hierarchy, but may appear anywhere below the top level.

	abstract class, base class, class, directed inheritance, ultimate base class
	About Class rules  Class hierarchy — Concepts and terms

Definitions