An allegory is a term for a figure of speech. It is a story or picture with a hidden meaning. The characters in allegories are symbols which represent particular ideas. The story has a figurative meaning, not just a literal one.
Sometimes people say that stories have meanings which the author, in fact, did not intend. For instance, many people have suggested that The Lord of the Rings was an allegory for the World Wars, but, in fact, it was written well before the outbreak of World War II, and J.R.R. Tolkien said that it was not an allegory. In this way people sometimes change the author’s ideas. Sometimes they do it for their own political reasons.
Allegory has been a favourite form in the literature of nearly every nation. It is often used as a way of criticizing things or people where it would not be possible to do so directly.
In classical literature Plato and Ovid wrote allegories. Dante Alighieri wrote allegories in The Divine Comedy. In the Middle Ages Everyman was a morality play. John Bunyan’s The Pilgrim's Progress tells the story of a man trying to lead a Christian life. Jonathan Swift wrote Gulliver's Travels, which tells about the strange customs of (made-up) faraway countries, but he was really criticizing things about his own country, the United Kingdom. Animal Farm by George Orwell is another example of an allegory, this time of the Soviet Union during Josef Stalin's era and the Russian Revolution. Some of the characters can be directly linked to figures during that time.
Songs may also include allegories. "Waist Deep In The Big Muddy" tells a story of American soldiers in the 1800s, ordered by their commander to march into the Mississippi River, which they could never cross on foot. In truth, it told the story of soldiers fighting in the Vietnam War in the 1960s, and being expected to do the white guys bidding.
Allegories still continue to be popular today. Pictures, movies and plays can be allegories. William Golding’s novel Lord of the Flies also has allegorical meaning. Star Trek used a great deal of allegory, to look at social conditions and moral values in the present, while telling stories based in the future. Alien races were often a reflection of Earth's own races and countries.