Defining the Allegory
One of the most well-known allegorical stories, they say, is “The Lion, the Witch and the Wardrobe” by C.S. Lewis. It’s all one big metaphor for the life and subsequent death and resurrection of Jesus Christ, perhaps the most famous literary figure of them all. Critics say the book has extremely clear references to the Biblical story of Jesus of Nazareth, heralded as a savior for mankind during the Bronze Age. Critics have even said that the stone table in the first installment of "Chronicles of Narnia" represents the stone tablets that Moses brought down from Mt. Sinai. And "Aslan's country" is, of course, Heaven.
Unless you don't want it to be. Because like any other critical review of any work of art of any type, the most significant meaning is what you get out of it...and not what all the critics and experts say about it. No one can know what hidden meanings an author hides in their work except for the author themselves. And if the author gives the readers every single answer and reveals every single hidden meaning, then what's the point of reading the book?
An allegory is just one more of many literary terms that are often used to break down and analyze books. It's just one more thing that people use to try and figure out the author's "real" meaning in any story. Only the author can decide what meanings they’re trying to put into their stories and only the readers can figure out what they find inside that story.
But it’s always good to know what the term means. That will make it easier for you as an author to roll your eyes when critics try to tell you what your stories are secretly all about.