A "Proton" refers to the protruding ball on the base of these climbing holds. On the base of these climbing holds are different ball-like shapes sticking out. It is these Protons that you are grabbing. The Protons range in size from high profile to squished oval shapes.
Setting with this style offers unique grip positions that you typically do not encounter. You can rotate these in many different ways to match, crimp, and pinch. The handholds also make for giant steep wall feet with a sweet spot to toe into.
Beginners should see this set as supplemental to the already existing positive holds on your wall.
There are 25 feet in the pack, so a beginner-level climber might see this set as all footholds.