The Bedford Glossary of Critical and Literary Terms - Ross Murfin 2018
Parable: A short, realistic, but usually fictional story told to illustrate a moral or religious point or lesson; a type of allegory. The parable differs slightly from the fable and the exemplum, two other types of allegory also designed to make a point, insofar as a true parable is composed or told in response to a specific situation and addresses that situation, at least implicitly, in an allegorical manner.
EXAMPLES: The most famous parables in Western literature are those told by Jesus and include the parables of the talents, the prodigal son, the rich man and Lazarus, the rich young ruler, and the lost sheep. Rachel Carson’s Silent Spring (1962) opens with an environmental parable titled “A Fable for Tomorrow,” a story about a catastrophic “blight” that affects an idyllic town. Its agents turn out to be pesticides; the moral is that humans bear responsibility for the natural environment.