When talking about verification is like asking our self are we building the system right? We always have to consider this question when we are talking bout verification. It is important that the process of the evaluating products of a development phase to find out whether they meet the specified requirements. Now when we are talking about validation we have to ask our self are we building the fight system? This is another question that validation people have to ask themselves since the process of evaluating product at the end of the development process to determine whether product meets the customer expectation and requirements. What make them apart it pretty much that the design validation shall prove the medical device meets the user needs and intended uses. And the design validation is a design controls activity that happens pretty late in the product development process but yet validation is a measure of one of the first activities- defining user needs.