In this chapter
Classifiers, special properties of attributes and operations, and different kinds of classes
Modeling the semantics of a class
Choosing the right kind of classifier
Classes are indeed the most important building block of any object-oriented system. However, classes are just one kind of an even more general building block in the UML—classifiers. A classifier is a mechanism that describes structural and behavioral features. Classifiers include classes, interfaces, datatypes, signals, components, nodes, use cases, and subsystems.
Classifiers (and especially classes) have a number of advanced features beyond the simpler properties of attributes and operations described in the previous part: You can model multiplicity, ...