Resultsets vs. Datasets (Devices)
Visual Studio 2005 generates both datasets and resultsets when you use the DataSource Wizard to create a new data source. Resultset code is more performant and significantly less verbose than dataset code. On the other hand, datasets are richer in the sense that they can hold multiple tables and maintain information about relationships between them. The programming model is significantly different between the two technologies.
You can choose to generate either or both of these structures to suit your purposes. This feature is provided for advanced developers. For more information, see.