ADO.NET is the primary relational data access model for Microsoft .NET-based applications. It may be used to access data sources for which there is a specific .NET Provider, or, via a .NET Bridge Provider, for which there is a specific OLE DB Provider, ODBC Driver, or JDBC Driver. ADO.NET is sometimes considered an evolution of ADO technology, but it is important to note that some major changes were made between the two. ADO.NET for database access, .NET remoting for distributed programming, .NET Security for access level security, ASP.NET for web application development and windows forms in smart client applications.

ADO.NET leverages the power of XML to provide disconnected access to data. ADO.NET was designed hand-in-hand with the XML classes in the .NET Framework — both are components of a single architecture.

ADO.NET and the XML classes in the .NET Framework converge in the DataSet object. The DataSet can be populated with data from an XML source, whether it is a file or an XML stream. The DataSet can be written as World Wide Web Consortium (W3C) compliant XML, including its schema as XML Schema definition language (XSD) schema, regardless of the source of the data in the DataSet. Because the native serialization format of the DataSet is XML, it is an excellent medium for moving data between tiers making the DataSet an optimal choice for remoting data and schema context to and from an XML Web service.

The DataSet can also be synchronized with an XmlDataDocument to provide relational and hierarchical access to data in real time. For more information, see Synchronizing a DataSet with an XmlDataDocument.