UML Communication Diagram Cheat Sheet:
Welcome to my UML 2.0 Communication Diagrams tutorial! If you haven’t seen my tutorial on Sequence Diagrams check it out first, because in this tutorial I explain Communication Diagrams by comparing them to Sequence Diagrams.
Communication diagrams are used to show links between participants. They focus in on which interactions are triggered and when. They also describe the order of events in all interactions. With the video and the cheat sheet above, you should be able to understand them in no time at all.