The Timeline enables you to organize objects and precisely control the timing of objects on slides. When you view the Timeline, you see a snapshot of a single slide and all of the objects on the slide.
You have full control over when objects display and can even set objects to display at the same time. For example, on a slide containing a caption, a highlight box, and an animation, you can have the caption appear, then the highlight box four seconds later, and then the animation two seconds after that. The Timeline also shows any audio associated with the slide or with objects on the slide, allowing you to easily coordinate the timing of audio with objects.
The Timeline provides an easy way to view, at a high level, all objects on a slide and how the objects relate to each other. The major components of the Timeline are objects, the header, and the playhead. The objects on a movie slide are displayed as stacked bars on the left side of the Timeline. The header at the top of the Timeline indicates time in seconds (and parts of seconds). The playhead shows the point in time in which the slide is being viewed. (Example)