Is there really a difference between z and b motherboards for oc?

So i was just wondering, is there a real difference between a good b760 and a bad z790 to not let you do any oc​? Like is it just to get us to spend more? Or is there a real difference that allows for z boards to have pc?

I was wondering becouse i recently bought a b760 motherboard that wasent really cheap, its a good one from the reviews ive seen, only problem is that i ddidnt know that only the z motherboards could be oc. ​