Data Providers
Data providers represent diverse sources of data such as SQL databases, indexed-sequential files, spreadsheets, document stores, and mail files. Providers expose data uniformly using a common abstraction called the rowset.
ADO is powerful and flexible because it can connect to any of several different data providers and still expose the same programming model, regardless of the specific features of any given provider. However, because each data provider is unique, how your application interacts with ADO will vary by data provider.
For example, the capabilities and features of the OLE DB Provider for SQL Server, which is used to access Microsoft SQL Server databases, are considerably different from those of the Microsoft OLE DB Provider for Internet Publishing, which is used to access file stores on a Web server.