An allegory (from Greek αλλος, allos, "other", and αγορευειν, agoreuein, "to speak in public") is a figurative mode of representation conveying a meaning other than the literal.
Allegory is generally treated as a figure of rhetoric, but an allegory does not have to be expressed in language: it may be addressed to the eye, and is often found in realistic painting, sculpture or some other form of mimetic, or representative art.
The etymological meaning of the word is broader than the common use of the word. Though it is similar to other rhetorical comparisons, an allegory is sustained longer and more fully in its details than a metaphor, and appeals to imagination, while an analogy appeals to reason or logic. The fable or parable is a short allegory with one definite moral.
Since meaningful stories are nearly always applicable to larger issues, allegories may be read into many stories, sometimes distorting their author's overt meaning. For instance, many people have suggested that The Lord of the Rings was an allegory for the World Wars, while in fact it was written well before the outbreak of World War II, and J.R.R. Tolkien's emphatic statement in the introduction to the American edition "It is neither allegorical nor topical....I cordially dislike allegory in all its manifestations, and always have done so since I grew old and wary enough to detect its presence."
Northrop Frye discussed what he termed a "continuum of allegory", ranging from what he termed the "naive allegory" of The Faerie Queene, to the more private allegories of modern paradox literature. In this perspective, the characters in a "naive" allegory are not fully three-dimensional, for each aspect of their individual personalities and the events that befall them embodies some moral quality or other abstraction; the allegory has been selected first, and the details merely flesh it out.