UML diagram types
UML differentiates two categories of diagrams - structure diagrams and behavior diagrams. In structure diagrams, the focus is on static structures. One example is the Component diagram, which is used to model the relationships between individual (software) components. By contrast, there are behavior diagrams, which focus on the dynamic behavior of a system. An example of a behavior diagram would be the State machine diagram, which shows how the instance of a class changes its internal state when particular events occur.
A typical feature of structure diagrams is that they show a selected section of a UML structure. They represent a view of a freely definable subset of this structure. By contrast, behavior diagrams (apart from the Use case diagram) describe the dynamic behavior of a particular element, normally a state machine, an activity, or an interaction.
UML defines the following diagram types:
Structure diagrams | Behavior diagrams |
|---|---|
The individual diagram types are briefly introduced below using simple examples relating to the topic of order processing. These examples are not intended to provide a complete or technically correct representation. They are merely intended to illustrate how particular situations relating to the topic can be represented using the different UML diagram types.