<P> Data validation is intended to provide certain well - defined guarantees for fitness, accuracy, and consistency for any of various kinds of user input into an application or automated system . Data validation rules can be defined and designed using any of various methodologies, and be deployed in any of various contexts . </P> <P> Data validation rules may be defined, designed and deployed, for example: </P> <P> Definition and design contexts: </P> <Ul> <Li> as a part of requirements - gathering phase in a software engineering or designing a software specification </Li> <Li> as part of an operations modeling phase ng </Li> </Ul>

Is a mechanism by which all the content in a specified storage areas are written as output