ASP.NET 4 Unleashed

The Ajax Vision

ASP.NET is a server-side technology for building web applications. Almost all the work happens on the web server and not the web browser. Whenever you perform an action in an ASP.NET page—such as clicking a button or sorting a GridView—the entire page must be posted back to the web server. Any significant action on a page results in a postback.

If you think about it, this is incredibly inefficient. When you perform a postback in an ASP.NET page, the entire page must be transported across the Internet from browser to server. Next, the .NET class that corresponds to the page must re-render the entire page again from scratch. Finally, the finished page must be sent back across the Internet to the browser. This whole long, slow, ...