Difference between HttpHandler and MVC Controller

Check out these links

http://stackoverflow.com/questions/856006/asp-net-mvc-vs-webforms-vs-http-handlers-ashx-which-is-the-most-lightweig

http://www.hanselman.com/blog/BackToBasicsDynamicImageGenerationASPNETControllersRoutingIHttpHandlersAndRunAllManagedModulesForAllRequests.aspx