A UML activity diagram is a cognitive diagram that depicts the behavior of a system. An activity diagram shows the control flow from a starting point to a finishing point, highlighting the various decision paths while performing the activity. The activity diagram is another important UML diagram for describing the dynamic aspects of the system. The UML activity diagram is essentially a flowchart representing the flow from one activity to another. The activity can be described as a system operation. The control flow is directed from one process to the next. This flow can be sequential, branched, or concurrent. Activity diagrams cater to all types of flow control by using various elements such as fork, join, etc.
