Usually, a record validation rule compares the values of two or more fields.
A field validation rule checks input to a field, and is applied when the focus leaves the field.
A record validation rule checks input to one or more fields is applied when the focus leaves the record.
When you define rules for tables, those rules apply when you import data.
To add validation rules to a table, you open the table and use commands on the Fields tab of the ribbon.
A control can have a different validation rule from the table field to which the control is bound.
This is useful if you want the form to be more restrictive than the table.
For more information about data types, field sizes, and input masks, see the article Introduction to data types and field properties.
You can define validation rules for table fields and for controls on forms.
The steps in the section Add a validation rule to a control on a form, later in this article, explain how to add rules to the properties in individual controls.