- abstract class
A class that has no instances. An abstract class is written with the expectation that its concrete subclasses will add to its structure and behavior, typically by implementing its abstract operations.
- abstract operation
An operation that is declared but not implemented by an abstract class.
The essential characteristics of an object that distinguish it from all other kinds of objects and thus provide crisply defined conceptual boundaries relative to the perspective of the viewer; the process of focusing on the essential characteristics of an object. Abstraction is one of the fundamental elements of the object model.
- access control
The mechanism for control of access to a model element, for example, to the contents ...