"The vast majority of people think that the terms “icing” and “frosting” are interchangeable. This is not the case. Icing is made with sugar and liquid and is generally (there are a few exceptions, such as fondant) pour-able. Think pound cake and donuts. Frosting is made with sugar and fat, such as butter or shortening, and is generally fluffy and spreadable. Varieties of frosting include buttercream and cream cheese"