Mozzarella is a traditional southern Italian cheese made from Italian buffalo milk by the pasta filata method. Stretched curd cheeses manufactured from this technique undergo a plasticising and kneading treatment of the fresh curd in hot water, which gives the cheese its fibrous structure.

Mozzarella received a Traditional Specialities Guaranteed certification from the European Union in 1998. This protection scheme requires that mozzarella sold in the European Union is produced according to a traditional recipe.

Italian buffalo milk is not consumed as a beverage but is used for making mozzarella, ricotta, yogurt and similar products. The milk of the Italian Mediterranean buffalo is three times more expensive than cow's milk and is costly to ship.

Most of the mozzarella cheese you see in the supermarket is made from cow's milk. Mozzarella cheese is not aged like most cheeses and is actually best when eaten within hours of its making.

More Info: en.wikipedia.org