Gatharing Requirement(SRS)------> User Acceptence Testing
       \                           /
  High Level Design(HLD)----> System Testing
         \                        /
    Low Level Design(LLD)--> Integratioon Testing
           \                    /
     Program specification------> Unit Testing              
	                      
                \         /
                 \       /
                  \     /
                   \   /
               coding/Testing  

  V model is software developement life cycle model. v for 
verification and validation model.The main advantage of the 
v model is parallel processing 
verification means contacting the meeting and reviews.
validation means actual testing.
verification contain 4 stages 
1.Gathering req: To prepare the SRS document
2. HLD: To prepare the main functionality of the application
3. LLD: To prepare the sub functionality of the application
4.Pgm Spec: To explain the each and every functionality of 
the application
validation also contain 4 stages:
1. Unit testing: To test the appl based on the Pgm Spec
2.Integration Testing: To test the appl based on the LLD
3.System Testing: To test the appl based on the HLD
4.UAT : To the appli based on the Gathering the req