Yes it is 3 rounds so to speak of 12 movements.
So basically lets use a bicep curl.
1st round (set), raise and lift the bicep while holding the dumbell 12 times. Take a rest in between doing it again by either 1-moving to another exercise like circuit training or take a rest for a 45-90 secs and do the bicep curl again or 2nd round (set) and then onto 3rd.
If starting out doing a full body routine make sure to get in good compound movements. Compound movements are basically exercises that workout a lot of muscle groups at one time like squats, deadlifts, bent over rows. Isolated movements work just one area or has low secoundary muscle work like bicep curl.
So when putting a full body routine together or using a pre-made one you want to make sure it has more compounds than isolates.