Answer:
Validation is the process carried out by the computer system to check that the input data meets its result according to the requirement in the validation rules. This process is basically used to avoid the data entry error in the system.
The main purpose of validation is to make sure that the given data or input is logically correct and properly complete.
Different kinds of validation are:
Keyword validation : It is basically used as keywords like and between and not to restricted type of the data.
Input mask validation property: This property are useful in data entry operations in the file.