The short answer: Your OLE DB driver use an ODBC driver to access the Microsoft Access .mdb file.
An OLE DB driver can be a wrapper for an ODBC driver. That means that it is essentially using an ODBC driver under the hoods to connect to and use the database. It can be a layered architecture. A lot of OLE DB drivers are not using ODBC to do their work. OLE DB allows you to connect to non-relational / non-SQL oriented data sources. ODBC is restricted to table-oriented sources unless the driver tries to mimic table-orientation where there is none.
The ODBC-driver that the OLE DB-driver is using is giving you an error message. Microsoft has something they call "Microsoft OLE DB provider for ODBC".
