A fable is a short story, in prose or verse, that features animals, mythical creatures, plants, inanimate objects, or forces of nature which are anthropomorphized (given human qualities), and that illustrates a moral lesson (a "moral"), which may at the end be expressed explicitly in a pithy maxim.
The word "fable" comes from the Latin "fabula" (a "story"), itself derived from "fari" ("to speak") with the -ula suffix that signifies "little".