UML defines nine types of diagrams: class (package), object, use case, sequence, collaboration, statechart, activity, component, and deployment.
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Class Diagrams Class diagrams are the backbone of almost every object oriented method, including UML. They describe the static structure of a system. |
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Package Diagrams Package diagrams are a subset of class diagrams, but developers sometimes treat them as a separate technique. Package diagrams organize elements of a system into related groups to minimize dependencies between packages. |
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Object Diagrams Object diagrams describe the static structure of a system at a particular time. They can be used to test class diagrams for accuracy. |
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Use Case Diagrams Use case diagrams model the functionality of system using actors and use cases. |
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Sequence Diagrams Sequence diagrams describe interactions among classes in terms of an exchange of messages over time. |
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Collaboration Diagrams Collaboration diagrams represent interactions between objects as a series of sequenced messages. Collaboration diagrams describe both the static structure and the dynamic behavior of a system. |
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Statechart Diagrams Statechart diagrams describe the dynamic behavior of a system in response to external stimuli. Statechart diagrams are especially useful in modeling reactive objects whose states are triggered by specific events. |
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Activity Diagrams Activity diagrams illustrate the dynamic nature of a system by modeling the flow of control from activity to activity. An activity represents an operation on some class in the system that results in a change in the state of the system. Typically, activity diagrams are used to model workflow or business processes and internal operation. |
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Component Diagrams Component diagrams describe the organization of physical software components, including source code, run-time (binary) code, and executables. |
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Deployment Diagrams Deployment diagrams depict the physical resources in a system, including nodes, components, and connections. |