Formats are the extra characters, spacing and attributes that can be applied to a data type to format data when it is entered or displayed. For example, a string data type for a phone number can have a format applied to it so a field using the data type will display a phone number as (555) 123-4567 instead of 5551234567.
Formats are stored as separate resources, but are applied to data types to help define how information is displayed in a field at runtime. A single format resource can be used by several data types. Perhaps the easiest way to understand what formats are and how they’re used is to view them as data “masks” that simply change the look of the information in a field without changing the actual information itself.
Information about formats is divided into the following sections: