The application life cycle has the following stages:
First the request will be made by the user to access an application resource or a page after this the request will be sent to the browser sends to the web server.
A request will be received by a unified pipeline first then the below events will take place:

• An object of the class ApplicationManager is created.
• After this for providing the information about the resource for this an object of the class HostingEnvironment is created.
• Finally the top level items in the application are compiled.

Response objects such as HttpContext, HttpRequest and were created and initialized.

An instance of the HttpApplication object is created and assigned to the request.

HttpApplication class processes the request here to process the request different events were raised, the events raised were:

• Request will be start of by the user
• After this IIS will first receive the request then it will be checked with ISAPI
• Check for the AppDmain.

  1.  If application domain exists, use it.

  2. If AppDomain does not exist create it.

• Then the core objects for HTTPContext, HTTPRequest and HTTPResponse will be created.
• After this it will check whether the HTTPApplication object exist or not:

           1. If it exist then it will pass on the core objects.

           2. But if it doesn't then it will create it first, then pass the core objects.

• The request will be processed by HTTPApplication object.

               1. HTTPApplication begin, authentication and authorization events will run.

               2. The request will then be passed to the Page.

               3. Page events and complete Page life cycle will run.

• Finally the HTTPApplication object will run the cleanup activity the it will end events and pass on the response to the user.