ADO.NET is the data access component for the .NET Framework.
ADO.NET leverages the power of XML to provide disconnected access to data. ADO.NET is made of a set of classes that are used for connecting to a database, providing access to relational data, XML, and application data, and retrieving results. ADO.NET data providers contain classes that represent the provider's Connection, Command, DataAdapter and DataReader objects (among others).
The following figure shows how ADO.NET fits into the communication between a Web client and the DBMS.