Oyster is a kind of mollusk, belonging to Oyster family. They usually grow on rocks or shells in the sea, and can also grow in fresh water. The oyster has two shells, the shell is gray or brown, and the inner shell is smooth pearl color. There is a soft body inside the oyster, which can be eaten. Oyster is a kind of food with high protein and low fat. It is rich in minerals such as zinc, iron, calcium, vitamin B12 and other nutrients, which helps to strengthen immunity, promote bone health and maintain normal function of nervous system. Oysters can be eaten raw or cooked, which is a very popular seafood food.