First, you have to know that JSF saves and restores the view state between requests using the ViewHandler/StateManager API. JSF does this during its lifecycle, the view state is saved in the session (or on the client machine) at the end of a request and is restored at the beginning of a request.

JSF uses this technique because it needs to preserve the views state over the HTTP protocol, which is a stateless protocol. Since JSF is stateful, it needs to save the state of views in order to perform the JSF lifecycle over multiple requests from the same user. Each page has a view state that acts as a ping-pong ball between the client and the server. A view is basically a component tree that may be dynamically changed (altered) during HTTP GET and POST requests. Each request will successfully go through the JSF lifecycle only if the component tree was previously saved and is fully capable to provide the needed information, that is, Faces Servlet succeeds to call the needed...