ADO uses the facilities of OLE DB to provide the unified data access. In fact, ADO is the higher-level data access from Universal Data Access technology group. Within the UDA there are a number of data access technologies, however, ADO and OLE DB are the primary focus in DNA applications. OLE DB is the underlying technology that ADO and other Data Source technologies use. OLE DB is a specification and implementation for building drivers for both aspects of the data access problem.
Providers are the implementation of a driver to enable Consumers to access the data.
OLE DB enables providers to work against a code base and conceptual framework in order to enable conformance to a data object model that all consumers can access.