Which term describes a short scene or story?

The term that best describes a short scene or story is "vignette." A vignette is typically a brief and evocative description that captures a moment, scene, or character, often focusing on the mood or emotion rather than the plot. It can stand alone as a complete piece of writing or be part of a larger work, and it is often used to illustrate a theme or idea.

In contrast, an episode usually refers to a segment or part of a larger story, often within a series. A sketch, on the other hand, often implies a rough or incomplete outline, which may not convey a complete idea or emotion as a vignette does. Lastly, a narrative refers to a broader term that encompasses any story, including longer forms such as novels or films, and is not limited to the short format implied by the question. Thus, the specificity of "vignette" in describing a short, descriptive piece makes it the correct choice.