Software Architect's Handbook

Generalization/specialization

Generalization is the process of abstracting common attributes and operations into a base class. The base class is sometimes referred to as the superclass, base type, or parent class. Generalization is also known as inheritance. The base class contains general attributes, operations, and associations that are shared with all of its subclasses. Generalization is graphically represented with a hollow triangle on the part of the connecting line that is closest to the base class.

Specialization is the converse of generalization in that it involves creating subclasses from an existing class. Subclasses are sometimes referred to as a derived class, derived type, inheriting class, inheriting type, or child class.