Text Box Control (Forms and Reports) [Access 2003 VBA Language Reference]
Text boxes on a form or report display data from a record source. This type of text box is called a bound text box because it's bound to data in a field. Text boxes can also be unbound. For example, you can create an unbound text box to display the results of a calculation, or to accept input from a user. Data in an unbound text box isn't saved with the database.
Note This control should not be confused with the Dynamic HTML text box control used on a data access page. For information about a text box control on a data access page, see Text Box Control (Data Access Pages).