Hi Sarika,

UML (Unified Modeling Language) is a modeling language that helps analysts (and others) specify, visualize, and document models of software systems (including structure and design).

UML 2.0 defines 13 types of diagrams which are divided into 3 main categories:

• Structure Diagrams: Class Diagram, Object Diagram, Component Diagram, Composite Structure Diagram, Package Diagram, and Deployment Diagram.
• Behavior Diagrams: Use Case Diagram, Activity Diagram, and State Machine Diagram.
• Interaction Diagrams:, Sequence Diagram, Communication Diagram, Timing Diagram, and Interaction Overview Diagram.

For more details, check out the official UML page: http://uml.org/

- Adrian