Activity Diagram
State diagram with extra steps
In activity diagram, most transitions are caused due to internal events
Concurrency Representation
Forks
- one incoming and multiple outgoing
Joins
- multiple incoming and one outgoing
- outgoing triggered by incoming
- incoming triggered in separate threads
Rendezvous
- multiple incoming and multiple outgoing
Types of Nodes
- Decision Node: Diamond
- Merge Node: Single Line

