How does Potential Work?

I'm very confused about how it works. I've looked at some guides and they are really confusing.

I think it sort of gives stats but I don't know how to use them.

Could anyone explain how it works and how to use it?

 

U will need a bs(blacksmith) to make high prof and with high prof u can use another type of bs to stat it ex : matk 7% int 7% 11

 

What is prof?

Still confused.

 

Thanks for the help, but I'm not looking for specific formulas. I just want to know where you go (in game) to use the potential.