After final release, the validation stage checks whether requirements relating to a specific intended use of a software component or application have been fulfilled (ISO 9000).
In ISO 9000 terminology, this refers to checking a software in development against orginal specification documentation.
In development jargon, it means using mathematical formulae to prove that a component or application works as intended.
Refers to a framework for software development whose aim is to describe development as a complete life-cycle starting at an analysis of requirements and going through to acceptance, use and maintenance.
The V-model sets checks and tests for each phase it describes. It describes how components and versions produced before the end of the project can be tested, verified and validated.
There are now several versions of the model, such as v-model 97 and v-model XT.
Cf. Wikipedia on v-models.