Check Box Control (Forms and Reports) [Access 2003 VBA Language Reference]
A check box on a form or report is a stand-alone control that display a Yes/No value from an underlying record source.
Note This control should not be confused with the Dynamic HTML check box control used on a data access page. For information about a check box control on a data access page, see Check Box Control (Data Access Pages).
When you select or clear a check box that's bound to a Yes/No field, Microsoft Access displays the value in the underlying table according to the field's Format property (Yes/No, True/False, or On/Off).
You can also use check boxes in an option group to display values to choose from.
It's also possible to use an unbound check box in a custom dialog box to accept user input.