A transition may branch into two or more mutually exclusive transitions. A branch and its subsequent merge marking the end of the branch appear in the diagram as hollow diamonds. A transition may fork into two or more parallel activities. The fork and the subsequent join of the threads coming out of the fork appear in the diagram as solid bars. A component is a code module.
Component diagrams are physical analogs of class diagram.
Deployment diagrams show the physical configurations of software and hardware. The following deployment diagram shows the relationships among software and hardware components involved in real estate transactions. The physical hardware is made up of nodes . Each component belongs on a node. Components are shown as rectangles with two tabs at the upper left.