The general recommendation is 1-3 sets of each exercise, and 8-12 repetitions per set. So they might be doing just one set and moving on to the next exercise, or they might be doing one set of one, one set of another and then going back for a second set, etc. There are different ways you can structure the workout.
"You may have a fresh start any moment you choose, for this thing that we call "failure" is not the falling down but the staying down." Mary Pickford
"No matter how slow you go, you are still lapping everybody on the couch."