Verification vs Validation
Verification checks 'are we building the product right?' Validation checks 'are we building the right product?'
Full definition
Verification and validation are two complementary quality activities that are often confused.
Verification ('Are we building the product right?'): Checks that the software conforms to its specification. Activities include code reviews, walkthroughs, inspections, and static analysis. Verification doesn't require running the software.
Validation ('Are we building the right product?'): Checks that the software meets the user's actual needs and expectations. Activities include functional testing, user acceptance testing (UAT), and beta testing. Validation requires running the software.
Both are essential. You can build software that perfectly matches the spec (verification passes) but doesn't solve the user's problem (validation fails).
This is a classic ISTQB exam topic — know the definitions cold.
Interview tip
Remember the shortcut: Verification = specification match, Validation = user satisfaction.