Since most “interesting” websites are data-driven sites, it comes as no surprise that the DataGrid is one of the most often used controls in ASP.NET 1.x applications. In fact (...shameless plug warning...), I've written an entire book on the DataGrid, ASP.NET Data Web Controls Kick Start). The DataGrid was a huge improvement over data display techniques used in classic ASP (namely, loops in server-side script intermixed with emitting HTML), making it super easy to display data and only slightly more difficult to add common data display tasks, such as formatting, paging, sorting, editing, deleting, and so on. Additionally, while binding data to a DataGrid was simply - just a few lines of code - it still required hammering out code. Bleh.
ASP.NET 2.0 still includes the DataGrid for backwards compatibility, but chances are you'll never use it when creating a new ASP.NET 2.0 page. This is because the DataGrid has been greatly improved in 2.0's new GridView control. The GridView introduces more properties and events than the DataGrid and allows for paging, bi-directional sorting, editing, and deleting support without writing any code. Additionally, ASP.NET 2.0 includes data source controls, which are declarative controls that can be used to access data. The result? You can bind data to a GridView control in an ASP.NET 2.0 page without writing a lick of code. To put it another way: you can create a fully functional, aesthetically-pleasing data-driven Web page that allows updating, deleting, paging, and bi-directional sorting in about three minutes. Honest.
If you are wanting to learn more about the GridView check out my latest content on MSDN Online: GridView Examples for ASP.NET 2.0. There are a ton of examples, screenshots, code snippets... to give it some scale, the Word document that contained this content clocked in at over 120 printed pages. It's like a mini-book available online for free. Enjoy!