What is the collapsed and expanded timeline?

The collapsed timeline is the default experience in the Studio. 

To expand the timeline, click on the expansion caret and more details will appear for editing.

Adjust timings, effects, and other actions in the detailed track by clicking and dragging, or right-click, to copy, paste, and delete items.

Re-size the entire timeline by moving the cursor over the edge of the timeline and dragging up or down.

Zoom in and out of the timeline using the zoom controls found in the bottom left corner of the timeline.