In a general sense, an ingredient is a substance which forms part of a mixture. In cooking, recipes specify which ingredients are used to prepare a dish. Many commercial products contain secret ingredients purported to make them better than competing products. In the pharmaceutical industry, an active ingredient is the ingredient in a formulation which invokes biological activity.
National laws usually require prepared food products to display a list of ingredients and specifically require that certain additives be listed. Law typically requires that ingredients be listed according to their relative weight within the product.
