This workout really focuses on the legs and the core. Most of the exercises are unilateral (single sided) to help you work on any imbalances that you may you have. These can get hidden in bilateral exercises, where the stronger or more dominant 'side' leads the way. And we all know that imbalances can increase the risk of injury and pain (not necessarily through working out, but through life!) so it really is good to regularly include single side work. The core also has to work hard when you start doing things on one side, in its stabilising and counter balancing role - so kill two birds with one stone with this workout (horrible saying that, isn't it?!).
Within this workout, if you feel or know you have a 'weaker' side, then start each exercise with that side. If you start with your stronger side, it’s unlikely you can match the reps with the weaker side, meaning this side will never 'catch up'. It is better to 'do more' with the weaker side, or match reps and weight with the good side so strength levels start to even out.
Here is a instruction video of how to do each exercise:
And here is a follow along video of one circuit: