Apart from the two different types of grips, the grip even goes more in depth than that as well. For instance, you can either have a weak grip or a strong grip and this is dictated by how many knuckles you can see on the hand that is on top of the grip. If you see two knuckles at address on the grip, then you have a neutral grip. If you see less than two it is considered weak, and if you can see more than two it is strong grip. Most professional golfers are somewhat in the neutral and to the strong grip, so weak grip is almost seen as bad for golfers. Here in this picture Tiger has a neutral to a strong grip.