Voisins coverage question?

so i’m mostly a slots guy but lately i've been lurking the roulette tables, and i keep seeing these folks talking about voisins bets. from what i’m picking up, it covers a chunk of the wheel, but i keep getting lost when people mention “full voisins” or partial voisins or mixing up with tiers and orphelins. is there a clear visual of what exactly counts as voisins? or do people just make up their own version sometimes? kinda bugs me because i can’t tell if i’m missing out on a smart bet or if it’s all just superstition in disguise

it looks like you’d need a pretty hefty chip stack to cover all those numbers at once, especially if you want some side action on the neighbors. i’m used to working promotions and bonuses, so i'm always thinking about coverage vs payout, but roulette seems all about these patterns and traditions i don’t totally get. just wondering if any of you have a clear approach to voisins, or if it’s really just a ritual for table regulars.