Which cheese is commonly used for a Caprese salad?

Caprese salad is an Italian salad, made of sliced fresh mozzarella, tomatoes, and sweet basil, seasoned with salt, and olive oil. It is usually arranged on a plate in restaurant practice. Like pizza Margherita, it features the colors of the Italian flag: green, white, and red. In Italy, it is usually served as an antipasto (starter), not a contorno (side dish), and it may be eaten any time of day. The Caprese salad is one form of a Caprese dish; it may also be served as a Caprese pizza, pasta, or sandwich.

Source: Wikipedia