LINQ to SQL is an O/RM (object relational mapper) that ships in .NET 3.5, and which allows you to model a relational database using .NET classes.  You can then query the database using LINQ, as well as update/insert/delete data from it.  LINQ to SQL fully supports transactions, views, and stored procedures.  It also provides an easy way to integrate data validation and business logic rules into your data model.

The easiest way to get started with an ASP.NET Dynamic Data site is to add a new LINQ to SQL data model to your project (right-click->add new item->LINQ to SQL Classes item).  This will bring up the LINQ to SQL class designer.  Drag database tables from your server explorer to define a set of classes (with relationships) for your database schema:

Figure 4