Timeline

The Timeline window organizes the elements of your scene into rows.

The layering order of the rows determines the composition order of layers when you export or playback your animation after selecting the Timeline Current Scene option in the Export Movie dialog box.

The Timeline window organizes elements differently than the Exposure Sheet.

The Timeline window displays the timing of pegs, effects and cameras. The Timeline allows you to track entire element layers, rather than the contents of each cell.
Unlike the Exposure Sheet, which displays the breakdown of elements in each frame of your animation, the Timeline window shows each element in your scene, and when it is used in a frame.

To activate the Timeline window:

Select Window > Show/Hide Timeline.