After a long journey, we are at a step in SDLC where we have implemented what we think will solve the initial problem of match the initial requirements. After being done coding, it is very possible that the system has some mistakes and releasing it as is would end in a very bad disaster.That’s why Verification and Validation are parts of SDLC.
As a whole, verification and validation refer to making sure the project does what it’s required to do. Still, there are differences between the terms.
Verification focuses on the project as it evolves in development. According to SoftwareTestingFundamentals, it happens at every phase of the project to ensure you are going in the right direction. The main goal of verification is to make the product meet the requirements. This means we are dealing with the direction the projects is taking.
On the other hand, validation focuses on the code and making sure it works. Testing is the most obvious and important way to validate. At this step you want to ensure the software is ready to be used by its intended users without problems.
The order of both can be altered but verification usually comes first.