ADO.NET is the set of classes and tools built into the .NET Framework that allow you to create powerful, scalable, and reliable data-driven applications. Using ADO.NET, you can connect to databases of all sorts including SQL Server, Oracle, Microsoft Access, and even some other less common database formats. When connected to a database, you can query and manipulate data in a wide variety of ways.
ADO.NET is an extremely large topic. As such, this one chapter won't cover all of it. This chapter focuses on the fundamentals of ADO.NET programming: using the data providers, connecting to a database, and performing data query and manipulation operations. Other chapters (such as Chapters 18, "Advanced ADO.NET Techniques," and 19, "Working with ADO.NET Data Providers") will show you some more advanced features of ADO.NET, and Chapter 20, "Strongly Typed DataSets," will give you a look at programming with SQL Server 2005 using C#.