Frosting - Frosting is a thick creamy topping used to decorate desserts such as cakes, and cupcakes. Some of the basic ingredients are powdered sugar, butter, and a small amount of water or milk. Other ingredients are usually added for texture, color, and taste. There are many different recipes for frosting that you can make. One is buttercream. Buttercream is thicker than powdered sugar icings and glazes. Buttercream frosting is made with powdered sugar and extra butter than icings and glazes. There are a few varieties of buttercream recipes using different ingredients, including orange juice or lemon juice. But they use less of the liquid you would use in icings or glaze, hence making it thicker. Some buttercream recipes even call for heavy cream in them. Buttercream frosting is easy to spread on cakes, cupcakes, muffins, and the like. You can make this buttercream frosting at home or buy it in the grocery store where all the cake mix and frostings are. Buttercream is the frosting most folks buy at the grocery store to decorate homemade birthday cakes and cupcakes. Icing is prepared with powdered sugar and "more milk, water, or juice" making it thinner than frosting. Icing can be spread or brushed on desserts such as cookies, pastries, and the like. Royal Icing - And then there is royal icing, made with powdered sugar, pasteurized liquid egg whites (or meringue powder), vanilla or your choice of extract (optional), and warm water or sometimes lemon juice or lime juice. Recipes do vary, though. It spreads smooth and hardens to a candy-like shell consistency. Royal icing is white, but you can add food coloring for all of your fancy decorating ideas. Used for cakes, cookies, wedding cakes, gingerbread houses, and more. Glaze – Powdered sugar glaze is the thinnest, with even more liquid added to the powdered sugar. Powdered sugar glaze is poured, spooned, or drizzled over the top of coffee cake, pastry, cinnamon rolls, banana bread, and the like. Its consistency is just about as thin as syrup, well, just about. :)