What is the difference between a riddle and a rhyme and a poem?

The difference between a riddle and a joke is that a riddle is in the form of a question in which the answer has a witty response. Whereas a joke is usually a story whereby the end of the story, known as the punch line, is what generates the laughter. For example, a typical riddle is something akin to, 'What has four legs in the morning, two in the afternoon, and three in the evening? Answer: man' A joke would be something akin to, 'Two women are discussing politics. One asks the other, 'So what do you think about Red China?" The other woman replies, "On a yellow table cloth, I think it would look beautiful!"