What is the difference between Verification and validation?

Verification and validation is done to make sure that the data is accurate and error free as the incorrect data can lead to data deformation or miss understanding of the document.

Data validation checks that data are valid, sensible, reasonable before they are processed it is a quality assurance process of establishing evidence that provides a high degree of assurance that the document accomplishes its intended requirements ,while data verification checks that the document meets specifications and that it fulfills its intended purpose this can be done by doing some checks like double entry so that the data must be entered twice or proof reading to make sure it is accurate and no errors in it, as for validations, it can be done by coding which means giving a code to specific words so that it would be easier to enter and the probability of mistake will be less, also format check can be done as it checks that the data are in a specific format, added to that, spelling and grammar checks for checking the language and writing mistakes.