ADO was first introduced as the data access interface in Microsoft Internet Information Server. ADO is implemented with a small footprint to provide minimal network traffic in key Internet scenarios, and a minimal number of layers between the front-end and data source. ADO is easy to use because it is called using a familiar metaphor: the OLE Automation interface, available from just about any tool and language on the market today. Because of its popularity as an easy-to-use, lightweight interface to all kinds of data, and the growing need for an interface spanning many tools and languages, ADO is being enhanced to combine the best features of, and eventually replace RDO and DAO, the data access interfaces in widest use today. ADO is in many ways similar to RDO and DAO; for example, it uses similar language conventions. ADO provides simpler semantics, which makes it easy to learn for today's developers.
ADO is designed to be the application-level interface to OLE DB, Microsoft's newest and most powerful data access paradigm. OLE DB provides high-performance access to any data source. Together ADO and OLE DB form the foundation of the Universal Data Access strategy. OLE DB enables universal access to any data. ADO makes it easy for developers to program. Because ADO is built on top of OLE DB, it benefits from the rich universal data access infrastructure that OLE DB provides.