...is the core data access technology for languages targeting the CLR. Use the System.Data.SqlClient namespace to access SQL Server, or providers from other suppliers to access their stores. Use System.Data.Odbc or System.Data.Oledb to access data from .NET languages using other data access technologies. Use System.Data.Dataset when you need an offline data cache in client applications.
(Optional) Find an Appropriate ADO.NET Data Provider for your Data Source ADO.NET includes built-in support for Microsot SQL Server databases along with OLE DB and ODBC data sources. Additional optimized third-party providers are available.