Frozen yogurt (also spelled frozen yoghurt; also known by the tradename Froyo) is a frozen dessert made with yogurt and sometimes other dairy products. It varies from slightly to much more tart than ice cream, as well as being lower in fat (due to the use of milk instead of cream). It is different from ice milk (more recently termed low-fat or light ice cream) and conventional soft serve. Unlike yogurt, frozen yogurt is not regulated by the U.S. Food and Drug Administration (FDA) but is regulated by some U.S. states. Frozen yogurt may or may not contain live and active bacteria cultures.