Beginning Web Development, Silverlight, and ASP.NET AJAX

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CHAPTER 2 ■ BASICS OF WEB DEVELOPMENT WITH ASP.NET
Architecture of ASP.NET
The simplicity of developing the stock quote application proves the power that ASP.NET
affords you as a web developer. Some fairly complex stuff was going on behind the
scenes, enabling you to focus on the business logic for your application, instead of all the
underlying plumbing necessary to get it to work.
Figure 2-22 shows how the underlying ASP.NET components all work together in an
ASP.NET application. At the bottom of the figure, you see the host operating system on
which the web server runs. The web server for ASP.NET can be Cassini or IIS. The web
server receives the incoming request from the browser and passes it to the ASP.NET runtime,
which sits on top of the operating system.
This runtime can use a global application file, called Global.asax, to manage functions
that are central to your web site. A number of modules are available to the runtime
for handling sessions, authentication, and caching.
Finally, your application or web service sits on top of these modules and executes.
Upon executing, it generates HTML markup that gets passed back to the process that
initiated the request through the web server.
Figure 2-22. ASP.NET architecture