In ASP.NET applications that do not use the MVC framework, user interaction is organized around pages, and around raising and handling events from the page and from controls on the page. In contrast, user interaction with ASP.NET MVC applications is organized around controllers and action methods. The controller defines action methods. Controllers can include as many action methods as needed.

When a user enters a URL into the browser, the MVC application uses routing rules that are defined in the Global.asax file to parse the URL and to determine the path of the controller. The controller then determines the appropriate action method to handle the request. By default, the URL of a request is treated as a sub-path that includes the controller name followed by the action name. For example, if a user enters the URL http://contoso.com/MyWebSite/Products/Categories, the sub-path is /Products/Categories. The default routing rule treats "Products" as the prefix name of the controller, which must end with "Controller" (such as ProductsController). It treats "Categories" as the name of the action. Therefore, the routing rule invokes the Categories method of the Products controller in order to process the request. If the URL ends with /Products/Detail/5, the default routing rule treats "Detail" as the name of the action, and the Detail method of the Products controller is invoked to process the request. By default, the value "5" in the URL will be passed to the Detail method as a parameter.

 
MVC ACTION METHOD Paramaters

MVC Action Method paramters are by default retrived from the requests data collection. The data collection include
-> Name Value Pair For Form Data
-> Query String Values &
-> Cookie Values