In UML, a relationship is a connection between model elements. A UML relationship is a type of model element that adds semantics to a model by defining the structure and behavior between model elements.
Category | Function |
---|---|
Activity edges | Represent the flow between activities |
Associations | Indicate that instances of one model element are connected to instances of another model element |
Dependencies | Indicate that a change to one model element can affect another model element |
Generalizations | Indicate that one model element is a specialization of another model element |
Realizations | Indicate that one model element provides a specification that another model element implements |
Transitions | Represent changes in state |
Relationships in class diagrams show the interaction between classes and classifiers. Such relationships indicate the classifiers that are associated with each other, those that are generalizations and realizations, and those that have dependencies on other classes and classifiers.
The following topics describe the relationships that you can use in class diagrams: