A metaphor is a figure of speech that, for rhetorical effect, directly refers to one thing by mentioning another. It may provide (or obscure) clarity or identify hidden similarities between two ideas. Metaphors are often compared to other types of figurative language, such as antithesis, hyperbole, metonymy and simile. One of the most commonly cited examples of a metaphor in English literature comes from the "All the world's a stage" monologue from As You Like It: