To go through 'Making movies make sense', use the right-hand arrow at the bottom of the page.
To go straight to a subject, use the menu on the left.
To go back to the start, use the 'Home' button at the top of the page.

You start and stop both kinds by pressing the ‘Play’ button.

Player bars with no pictures are sound clips.

You can also go through video clips by dragging the playhead.

Pictures with a player bar underneath them are video clips. Player bars with no pictures are sound clips.