The .ACCDB file format was created by Microsoft for their 'Access 2007' application - a relational database management system.

Access is part of the 2007 office suite and the arrival of the .ACCDB format is seen as the beginning of the end for the popular .MDB format. However, the .MDB format is supported by Access 2007 onwards.

The .ACCDB format is considered a step-forward from .MDB and supports many new features such as improvements in encryption, Outlook/SharePoint integration, the use of multivalued fields and the ability to include attachments in the database.

These database files can hold multiple data tables. Whilst working on an ACCDB file, the file becomes 'locked' and a new file is generated with the .LACCDB file extension until the database is available.