This is a shoulder and core strengthening exercise series with closed kinetic chain emphasis. Basically, that means your hand is on the ground (versus in the air holding weights or bands like most strengthening exercises). Completing exercises in this manner focuses on dynamic shoulder stability while also activating your core.
For all of the progressions in this video, start on your knees and complete 10 reps on each arm. Make sure not to let your back or shoulder blades sag down. One cue that may help with most of these exercises is to push your butt and shoulder blades to the ceiling.