In this video, we'll look at some examples of what moves first during both the takeaway and the downswing. As you'll see, there's a big difference in sequencing between your average player and a touring pro. Proper sequencing is one of the most important aspects of a functional golf swing. Without it, you basically don't have a chance to be good.
For more info on proper sequencing, you should check out Ben Hogan's book "Five Lessons: Modern Fundamentals of Golf."