Icing, Frosting whatever you call it, I mean the stuff that you cover (and sometimes fill) a cake with. Sweet, flavoured, coloured. Different types are suitable for different things, quick covering, ornate architectural constructions, or just to glue decorations on, see below and the recipes on the right for some advice.
Buttercream: Quick and easy, buttercream can be both spread or piped, and can be used to glue other decorations (just work fast before it dries). It's no good for sculpture, you'll never get a smooth finish, and you can't use it for flooding (plus it's rather over-sweet). Kids tend to love it though, and it's very easy to make an impressive looking cake by icing coloured rosettes of buttercream.
Glace Icing: Also very simple, it's particularly good for drizzling over cakes, but if thickened slightly can be spread on, and if thickened slightly more can be piped. It's not good for much more than simple round piping though, as it doesn't hold a shape.
Royal Icing: Takes a little more effort to make, but once you have you've got the best icing for piping and construction. Once dry, Royal icing is extremely hard (but also brittle) so it's just what you need if you're trying out flooding to build cake decorations.
Sugarpaste: A lot like playdough, sugarpaste can be rolled out to smoothly cover a cake, or coloured and molded into shapes and figures for decoration. If you're making a cake with the kids, this is the type of icing to use. Plus, you can buy it premade.
Frosting and Ganache: You can buy this in tubs, or make it yourself. Standard icing is a cooked icing, which needs to be applied quickly before it sets. Because of this, it's suitable just as a covering or filling, not for sculpture or decoration.
