text=An activity diagram is a UML diagram that shows the steps or tasks in a process. An activity diagram is very similar to a flowchart because it provides a view of the flow between activities in a process. Activity diagrams are similar to statechart diagrams because both diagrams model the dynamic parts of a system and they both belong to a state machine. Activity diagrams typically show how activities interact with each other, whereas statechart diagrams model the discrete stages of an object's lifetime.