According to Microsoft, ADO, DAO and RDO are all data access interfaces used in Visual Basic, but they differ in how recently they have been introduced and how flexible the interface is. As of 2014, ADO is the most recent, simple to use and flexible data access interface, and Microsoft feels it should be the data access interface used for Visual Basic programming.
Microsoft states that remote data objects and data access objects are outdated methods of data access interface in Visual Basic. Both RDO and DAO are still supported in Visual Basic for backward compatibility and in support of existing projects. ActiveX data objects were specifically built to interface with and use OLE DB, Microsoft's newest and most powerful data access paradigm. Due to the complexity of OLE DB, it should not be accessed directly. ADO functions as the interface allowing full use of OLE DB. ADO uses many commands similar to RDO and DAO and the OLE automation interface to facilitate and speed up retraining by individuals accustomed to the older data access interface systems. While ADO has a relatively simplistic interface, it offers a greater and more nuanced interface with OLE DB. Microsoft strongly suggests upgrading from RDO to ADO.