The most basic way of previewing frames is to manually preview by moving or dragging the current-time indicator.
The time ruler visually represents the time dimension of a composition, a layer, or a footage item. In a Layer or Footage panel, the time ruler appears near the bottom of the panel. For a Composition panel, the time ruler appears in the corresponding Timeline panel. The time rulers in different panels represent different durations. The time ruler in a Layer or Footage panel represents the duration of the contents of that panel; the time ruler in the Timeline panel represents the duration of the entire composition.
On a time ruler, the current-time indicator indicates the frame you are viewing or editing.
