What is "httpapplication"

Instances of the class HttpApplication are created by the ASP.NET framework, not by the user directly. An instance of the class HttpApplication is used to process many requests during their existence. However, it can process only one request at a time. Therefore, member variables can be used to store data per request.

An application generates events that can be handled by customizable modules, which implement the interface IHttpModule, or by event managers defined in the file Global.asax. Customizable modules that implement the interface IHttpModule may be placed in the folder App_Code or in a DLL in the folder Bin.

This module was introduced in version 3.5.