An ACCDB file is a database created with Microsoft Access 2007 or later. It typically contains data organized into tables and fields and may also include custom forms, SQL queries, and other data. ACCDB files replaced .MDB files.
ACCDB files are similar to MDB files used in previous versions of Access, but support additional functionality, which is led to their replacement of MDB files. Some enhancements of ACCDB files include the ability to store file attachments and other binary data, multi-valued field support, database encryption, and integration with MS Outlook and SharePoint.