Intuition is a layer of software that can handle certain tasks automatically, freeing application programs from some mundane responsibilities. Applications need not be notified when windows are resized, refreshed, moved to the front/back, activated or deactivated, iconified, and so on. (Of course, applications may still choose to handle these events themselves.) This is in direct contrast to operating systems like the Macintosh's, in which the application must respond to every event.