Most American pizzas use what they call mozzarella cheese, but the rubbery mess that is used is far from authentic mozzarella, which is a soft Italian cheese that is made fresh in small globes the size of a tangerine or smaller. It is made from the milk of the buffalo (no, not the bison- that's an American animal that we mistakenly call buffalo), an Old World relative of the dairy cow- think water buffalo. Get the idea? Fresh mozzarella in the US is often made from cows milk nevertheless (when was the last time you saw a water buffalo grazing by the side of the road) and is still delicious and much better (and more authentically Italian) than the mozarella you get in the dairy case of your local supermarket. The imported Italian stuff should be labeled mozarella di buffala in order to be the real McCoy. You can often find it in gourmet shops. Cooking hint: it holds MUCH more water than the domestic stuff, so slice it or grate it and press it or drain it before topping your pizza, to keep it from getting runny. Buon Apetito!