Summary

On the surface, ASP.NET looks much like its predecessor, ASP 3.0. It supports interspersed server-side script, has the same set of intrinsics available, and provides the same ability to mix static HTML layout with dynamic server-side code. Under the covers, however, ASP.NET is dramatically different. Instead of using script interpretation, each page is now compiled in its entirety to a class that derives from System.Web.UI.Page . The entire request processing architecture is now based on a set of classes that model each aspect of a request and its response. ASP.NET introduces a new technique called code-behind that involves injecting a class in the hierarchy between the Page base class and your .aspx file “generated class, creating a clean separation of page layout from server-side code. Finally, ASP.NET solves the headache of Web application deployment by using the shadow copy mechanism in .NET to load " shadowed " versions of your component assemblies, leaving the original assemblies unlocked and available for replacement without shutting down the Web server.