I was preparing some UML material the other day, and came across the graphic below which nicely lays out the different diagrams, and most importantly, shows that critical split between a Structure Diagram and a Behaviour Diagram.
When explaining UML to novices, I find that the structure vs behaviour split is often the “Ah Ha” moment when things fall into place. Without that, the names of the diagrams are just too much to digest in a single sitting.
For those wanting more info, check out UML-Diagrams.org

