Allegory- A text that can be interpreted to have a different meaning to that on the surface.

Example from the text-

Lord of the Flies has a surface meaning of trying to isolate younger people in society to see what they will do without the aid of adults. However, the deeper meaning or purpose of the book is to isolate people from normality and society to show how humans can posses killer instincts against one another.

Allegory: a representation of an abstract or spiritual meaning through concrete or material forms; figurative treatment of one subject under the guise of another.