Activity diagram
Appearance
An Activity Diagram is a diagram kind of the Unified Modeling Language.
Description
Activity diagrams represent the business and operational workflows of a system.
In UML 1.x, an Activity diagram is a variation of the UML State diagram where the "states" represent operations, and the transitions represent the activities that happen when the operation is complete.
The UML 2.0 Activity diagram, while similar looking to the UML 1.x Activity diagram, now has semantics based on Petri nets.
In UML 2.0, the Interaction Overview diagram is based on the Activity diagram.
Example