Retrieving and Modifying Data in ADO.NET
A primary function of any database application is connecting to a data source and retrieving the data that it contains. The .NET Framework data providers of ADO.NET serve as a bridge between an application and a data source, allowing you to execute commands as well as to retrieve data by using a DataReader or a DataAdapter. A key function of any database application is the ability to update the data that is stored in the database. In ADO.NET, updating data involves using the DataAdapter and DataSet, and Command objects; and it may also involve using transactions.