Each transition implementation is defined by its effect and duration. For example, the mover transition has the effect of moving a wrapped object from one point to another over a specific period of time. Likewise, the fader transition has the effect of applying a fade out effect to a wrapped object, gradually over some period of time. The interface provides APIs for stepping a transition effect and supplying notification at the completion of a transition effect. A transition is a passive object; it cannot do anything on its own. In order to progress through a transition, it must be inserted within a transition manager or be manually stepped by an application. The manager will be responsible for sending the step events to the transition. Please refer to ITransitionMgr interface for more details on how to customize managers.