I usually begin presentations on Atlas by saying “Atlas is Microsoft’s AJAX framework for ASP.NET.” That assumes everyone in the room knows what AJAX is. IBM’s Web site contains an excellent article describing the fundamentals of AJAX. It’s written for Java developers, but it cuts across language and platform boundaries and makes an excellent read for ASP.NET developers, too.

If you want to solidify your understanding of AJAX before tackling Atlas, this article is a great place to start.