UML modeling is not just about diagrams; it’s about capturing your system as a model-the diagrams are actually just windows into that model. A particular diagram will show you some part of your model but not necessarily everything.
Use Case
Interactions between your system and users or other external systems. Also helpful in mapping requirements to your systems.
Activity
Sequential and parallel activities within your systems.
Class
Classes, types, interfaces, and the relationships between them.
Object
Object instances of the classes defined in class diagrams in configurations that are important to your system.
Sequence
Interactions between objects where the order of the interactions is important.
Communication
The ways in which objects interact and the connections that are needed to support that interaction.
Timing
Interactions between objects where timing is an important concern.
Interaction Overview
Used to collect sequence, communication, and timing diagrams together to capture an important interaction that occurs within your system.
Composite Structure
The internals of a class or component, and can describe class relationships within a given context.
Component
Important components within your system and the interfaces they use to interact with each other.
Package
The hierarchical organization of groups of classes and components.
State Machine
The state of an object throughout its lifetime and the events that can change that state.
Deployment
How your system is finally deployed in a given real-word situation.
