Introduction - If you have any usage issues, please Google them yourself
UML includes things, relation, graph, expansion mechanism.
( 1).
Structure: class, interface, components and joints, etc..
Behavior: Interactive ( News ), the state and so on.
Packet: packet, subsystem and so on.
Annotation: annotations.
( 2) relationship
Dependent, Association ( polymerization, composite ), generalization, to achieve.
( 3) map
Use case diagram, diagram ( sequence diagram, collaboration diagram, class diagram, activity diagram ), state diagram and so on.
( 4) extension mechanism