V model is the combination of verification and validation.
verification is done by developer. validation is done by the
tester. In the verification side Design, Coding, Execution
and Implementation whereas in the validation side we had
done Unit testing, system testing, Integration Testing, User
Acceptance Testing.

The above answer is partially wright

V model is very simple, checking the application
simultaneously as they developing


Ex

 Business scenario's  \                /   UAT testing
                       \              / 
          SRS           \            / System testing
                         \          /
           HLD            \        /  Integration testing
                           \      /
                            \    /
             LLD             \  /   Unit testing
                              \/


 Business scenario's - as what the client originally want


 Business scenario's is documented that is SRS

HLD and LLD are documented based on the developer 

UAT User Accepting testing

Murali,
murali.indrani@gmail.com
9942999500
chennai

In V-Model the
strategy goes like this

 Gathering phase                                           
                User Acceptance Testing.

         Analysing
phase                                     System Testing
   
              Design Phase
             (HLD and
LLD)                           Integration Testing

                     Coding
phase              Unit Testing

                                            build


Here unit testing is done related to Coding
Integration testing is based on Design phase
System Testing is done related to Requirements (Analysing phase)
User acceptance is done based on Gathering phase.

V stands for verification and validation 

Verification used for document level testing

Validation used for programming level testing

BUssiness Requirements(BR)- ---------> User Acceptence Testing
    \                                       /
 System Requirements(SRS)----------> System Testing
      \                                    /

 High Level Design(HLD)---------> System ntegratioon Testing
        \                               /

Low Level Design(LLD)--------> Component Integration Testing
           \                         /
                                                             
        Coding  ------------>  Unit Testing
              \                    /

                \                 /

                    \           /

                        Build


V Model is a popular Software development model. It large
number of resources to implement.
In v model every development stage will have corresponding
testing stage.
Here test will be prepared in parallel with development phases.
i.e
After receiving  the business requirements are prepared 
then testing team will develop User acceptence Testcases.
But these testcases will be executed and the end of the project.

Here Business Requirements are very abstract in nature and
it talks just about What user/customer actually needs.
System Requirement Specifications will be prepared From
Business Requirements specifications.
SRS will be more elaborated then the Business requirements.
SRS tell what are system features need to be developed.
After seeing SRS Document Testing People will start 
preparing System Functional Test cases.

After receiving High level Design Doc,Testing people will
prepare the System Integration Test cases.
After seeing Low level Design doc,Development team will will
prepare the Component integration Test cases.
After coding development team will prepare uint test cases
and executes the unit test on the each individual unit or
function.
Thus there is a mapping between the each development  phase
with testing.