How Web MVC typically works
Typical server-side MVC implementation has one MVC stack layered behind the singe point of entry. This single point of entry means that all HTTP requests, e.g. http://www.example.com or http://www.example.com/whichever-page/ etc., are routed, by a server configuration, through one point or, to be bold, one file, e.g. index.php.
At that point, there would be an implementation of Front Controller pattern which analyzes HTTP request (URI at first place) and based on it decides which class (Controller) and its method (Action) are to be invoked as a response to the request (method is name for function and member is name for a variable when part of the class/object).