following link provides a reasonable description of OLEDB
http://database.ittoolbox.com/documents/popular-q-and-a/odbc-vs-oledb-2412In summary, is says
"OLEDB is the successor to ODBC, a set of software components that allow a "front end" such as GUI based on VB, C++, Access or whatever to connect with a back end such as SQL Server, Oracle, DB2, mySQL etal. In many cases the OLEDB components offer much better performance than the older ODBC.
OLEDB is a different type of data provider that came about with MS's Universal Data Access in 1996 and does not require that you set up a DSN. It is commonly used when building VB apps and is closely tied to ADO. It works with COM, and DCOM as of SQL 7.0."
So basically, is it a method to connect to the database. It does not restrict you to use a particular database product, as long as you find drivers for it - and most database providers also provide OLEDB drivers.
More info available all over the new using keyword OLEDB.
Have fun,
Sanna