Data policies are helpful to enforce data consistency by setting read-only and mandatory states. They can be quite relatable to UI policies, but the difference is UI policies are applied only to the data provided on forms using standard browsers. Also, it can apply rules to each data entered, like data entered through import sets, web services, email, or mobile UI. For example, if a mandatory field in the entered record is empty then it is possible to prevent the insertion of that record into the table by using data policy.
