Here's why:
* Parable: A simple story used to illustrate a moral or spiritual lesson. It often uses allegory and symbolism to convey its message.
* Fable: Similar to a parable, but often features animals as characters and emphasizes a moral lesson.
* Allegory: A story with a deeper, symbolic meaning. While it can teach a lesson, it often explores a more complex theme.
While all these terms can be used for stories with a moral message, parable is the most direct and specific term for a story written primarily to teach a lesson.