Example of Sequence Diagrams

Sequence diagrams contain the same information as Collaboration diagrams, but emphasize the sequence of the messages instead of the relationships between the objects. The arrows between the lifelines represent messages being sent between the objects. Sequence Diagrams clearly depict the sequence of events, show when objects are created and destroyed, are excellent at depicting concurrent operations, and are invaluable for hunting down race conditions.

Example of a Sequence Diagram of a Online Forum:

1. Registration:

2. Write Article: