How is a cheese it made?
Milk is split into curds and whey by the addition of rennet and starter culture. The curds are then separated and matured to make the cheese.
Cheese is vegetarian if it does not use animal rennet. There are vegan cheese substitutes as well, but they are not technically "cheese". Cheese in general is made with milk and enzymes. Traditionally the enzymes were made from animal rennet, which is not vegetarian. Nowadays technology exists to use vegetarian enzymes. Vegetarian cheese is made with vegetable rennet, instead of rennet from a cows stomach.