Orange, also known as sweet orange, is an evergreen citrus tree. The oil glands in the fruit peels emit an aromatic fragrance. Orange trees can grow up to 10 meters tall. They are divided into four categories: blond oranges, navel oranges, bitter oranges, and acid-free oranges. From the orange, one can obtain juice, the aromatic orange peel, and the peel oil, which is used in perfumery and food flavoring.