Allegory

As a literary device, an allegory in its most general sense is an extended metaphor. An allegory may be: 1) the representation of abstract principles by characters or figures; 2) a picture, book, or other form of communication using such representation; or 3) a symbolic representation which can be interpreted to reveal a hidden meaning, usually a moral or political one.

Quotes

 * I cordially dislike allegory in all its manifestations, and always have done so since I grew old and wary enough to detect its presence. I much prefer history, true or feigned, with its varied applicability to the thought and experience of readers. I think that many confuse 'applicability' with 'allegory'; but the one resides in the freedom of the reader, and the other in the purposed domination of the author.
 * J. R. R. Tolkien, The Lord of the Rings, Foreword to the Second Edition (October 1966)