Actually, this is more accurately the connection string to use the Jet 4.0 OLE DB provider for ADO, which I think was introduced with MDAC (Microsoft Data Access Components) v2.0 or 2.1.
This provider will communicate with either an Access 2000 database or an Access 97 database, but needs an Access 2000 database for some features (Select @@Identity comes to mind).
I use this provider if available vs. the ODBC Access driver (the Driver=Microsoft Access Driver *.mdb). There is also a JET.OLEDB.3.51 (I think it's .51) provider if you have problems with the 4.0 provider.