Stephen Walther has a great article on the life-cycle of a request being handled by the MVC Framework.
Here’s a extract from the top of his article, it goes on to explain each step in detail:
Overview of the Lifecycle Steps
There are five main steps that happen when you make a request from an ASP.NET MVC website:
1. The RouteTable is Created
This first step happens only once when an ASP.NET application first starts. The RouteTable maps URLs to handlers.
2. The UrlRoutingModule Intercepts the Request
This second step happens whenever you make a request. The UrlRoutingModule intercepts every request and creates and executes the right handler.
3. The MvcHandler Executes
The MvcHandler creates a controller, passes the controller a ControllerContext, and executes the controller.
4. The Controller Executes
The controller determines which controller method to execute, builds a list of parameters, and executes the method.
5. The RenderView Method is Called
Typically, a controller method calls RenderView() to render content back to the browser. The Controller.RenderView() method delegates its work to a particular ViewEngine