Final answer:
The .ACCDT file extension is used for Access 2007-2013 database templates, allowing for the creation of new databases with predefined structures.
Step-by-step explanation:
The file extension for an Access 2007-2013 database template is .ACCDT. When creating a database template in Microsoft Access, a user saves the file with the .accdt extension. This enables the user to create new databases with pre-defined structures and elements. As opposed to the .accdt extension, the .ACCDB extension is used for Access database files, the .MDB for Access databases prior to Access 2007, and the .MDE for a compiled version of the database that does not allow for the modification of forms and reports.