Types of UML Diagrams:
1. Use case Diagram
2.	State Diagram
3.	Class diagram,
4.	Sequence diagram
5.	Collaboration diagram


 Use case: A set of scenarios that describing an interaction
between a user and a system, including alternatives.

Use case diagram-Uses: 
 Used for describing a set of user scenarios
 Mainly used for capturing user requirements
 Work like a contract between end user and software developers

Use case diagram-Core components:
  a)	Actor b) Use case  c) System boundry

Use case diagram Relation's:
a)Association B) Generalization c) Include d) extend