Communication diagram VP-UML

I’m starting in VP_UML and like to know in which cases I can use communication diagram and what is the meaning (function) of the elements that can be add to the diagram (ex. package, subsystem, lifeline, swimlane…)
Does exist any information source about my doubts in the NET?

Thanks.

Thank you for your message. The communication diagram is best for showing the messages between the objects. The communication diagram shows you the messages without scrolling around the diagram (Sequence diagram that the messages between 2 objects may spread far away with many other messages in between). You can reference to the following document

http://www.omg.org/cgi-bin/doc?ptc/2004-10-02

If you have any further questions, please feel free to contact us again.

Best regards,
Rain