Product validation
Also called: validation vs verification, verification and validation
Product validation asks whether what was built serves the user and the business case. Verification asks only whether it matches the specification.
Verification and validation are different questions. Verification checks the product against its specification: does it do what the ticket says? Validation checks the specification against reality: is that what the user and the business needed?
A release can pass every test and still fail validation. The feature works as written and nobody can find it, or the flow is correct and takes eleven steps where the old one took four.
Validation happens early or it happens in production. I do it by tracing the journey in the design before build, questioning acceptance criteria in refinement, and raising friction as stories or low-priority defects while it is still cheap to change.