Butter is made from dairy milk, and margarine is made from vegetable oil. Both fats have the same number of calories per serving. Margarine sometimes contains less cholesterol than butter, but this depends on the types of oils used to make the margarine, says Mayo Clinic.
Anyone can make butter at home by churning, or agitating, milk until the fat separates out. Margarine, on the other hand, is made in factories through a series of chemical processes. Margarine contains varying amounts of saturated fat, depending on the brand. Butter contains cholesterol, but it also contains vitamins such as A, D, E and K.