Cake is a baked delicacy made from eggs (usually hen's), flour (usually self-raising) and butter (usually fattening). In polite society, cake is usually eaten in slices (often accompanying a really good cup of tea), although it may be eaten whole if it is very small or you are very hungry.
Despite its apparent simplicity, cake comes in many forms, and you should know of a few peculiarities before you sample some.
Fruit cake does not usually contain apples, lemons or mangoes, but generally includes raisins and, perversely, nuts (as in the derogatory expression "nutty as a fruitcake").
Chocolate cake is cake which contains chocolate, but a "cake of chocolate" is all chocolate and no cake, which may or may not prove to be a disappointment.
Most importantly, if someone offers you a cake of soap, do not eat it. Soap is a cleaning agent applied to the outside of the body using a sponge.
However, you may eat a sponge cake with no fear of ill effects.