Validation testing in software engineering is the review process that verifies that the software system produced meets specifications and achieves its purpose. They are also known as "User Acceptance Testing", PAU, which comes from the acronym in English for User Acceptance Testing (UAT). It is normally a part of a project's software testing process, which also uses techniques such as evaluations, inspections and walkthroughs. Validation is the process of checking that what has been specified is what the user really wanted.

It involves evaluating the system or part of it during or at the end of development to determine if it satisfies the initial requirements. The question to ask is: Is this what the client wants?

Check that the requirements are met:.