The part about semantics is getting clearer to me. Apparently, like Vitality pointed, it's more about relating the joysticks (or "directinput devices") to the various game genres and actions constants defined in the microsoft's dinput.h and then Action Mapping will simply consist of polling all the connect devices and informing the application when a keypress triggers an action.
This page http://msdn.microsoft.com/en-us/library/bb172238%28v=vs.85%29.aspx is the best documentation about the subject that I have found until now. Does anyone have another source of info to suggest?