V-models, also known as validation or verification models, are SDLC models where the process occurs sequentially in a V-shape. This method consists of associating a testing phase with each corresponding development stage. As each development activity is accompanied by a testing activity, the next test phase occurs only after the previous phase has been completed.

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  Validation: It is defined as a process that involves dynamic testing of software products by executing the code. This process validates whether we are building the right software that meets that customer's requirement or not. It involves various activities like system testing, integration testing, user acceptance testing, and unit testing.


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  Verification: The technique involves static analysis (review) without running the code. It is defined as a process that involves analyzing the documents. This process verifies whether the software conforms to specifications or not.  Its ultimate goal is to ensure the quality of software products, design, architecture, etc.