Mastering the English language is difficult enough without throwing the nuances of literature into the mix. The number of genres can be head-spinning, and then there's the seemingly endless list of literary terms such as dramatic irony, alliteration, narrative, and prose. The latter two get many people confused and lead to the question of what the difference between narrative prose and short stories is.
More Similarities Than Differences
Prose is any piece of writing that's not poetry. Narrative prose is a story with a plot and characters, and a short story is basically the same thing. Narrative prose can have some poetic elements including figurative language or imagery, but it's not written using a metrical structure or rhyme. The same generally goes for short stories -- neither type of writing is poetry.
One element that narrative prose typically has is dialogue between characters. However, a short story can go from beginning to end and never have any dialogue at all. Here's an example of narrative prose that contains dialogue:
"We're going to hike up the tallest mountain the state, and you're only taking a sandwich and two apples?", asked Meg. Dave wondered about his choice to pack such a scant lunch and then headed towards the pantry. "You're right", he said, "I should also bring a half dozen granola bars". Better equipped, the duo set off on their adventurous journey.
On the other hand, here's the same plot written as a short story without any dialogue:
As Meg and Dave prepared for their hiking trip, she looked through his backpack and spotted a very meager lunch. Meg wondered how he'd ever make it through the trip without passing out for lack of food. After pointing out that it would be best for them to have ample nourishment, Dave rethought his lunch plans and grabbed a handful of granola bars. Satisfied that they wouldn't starve while hiking on the mountain, Meg and Dave set off on their journey.
Fact vs. Fiction
As you can see, there's very little difference between narrative prose and short stories, especially when it comes to fictional writing. However, there's a type of prose called the narrative essay that deals with facts. When you write a narrative essay, you're retelling events in a structured way, but typically from the first or second person point of view.
Short stories can be nonfiction, but that's not usually the case. A literary genre called realistic fiction is popular, and it involves a plot that's made up but could realistically happen. For instance, the earlier example of Meg and Dave going hiking could be turned into a realistic fiction story because the entire scenario could actually happen to people in real life. However, it wouldn't qualify as a narrative essay because it contains no facts.
Length
The lengths of short stories and narrative prose is something that can vastly differ. Generally, a short story is no longer than 7,500 words. There is a type of short story called flash fiction that's super short and isn't usually more than a page long -- the second story example given above is basically flash fiction.
Narrative prose, however, can be very long, it just depends on the author, purpose of writing the story, and the plot itself. With a huge cast of characters and a plot with many twists and turns, a piece of narrative prose can go on for hundreds of pages.
A short story, however, must be short to actually fit the definition. Those who are just starting out writing fiction often find it more difficult to write short stories because the author has to be concise to fit in every part of the plot. It's challenging to convey characters' emotions, actions, and evoke feelings in readers when your word count is limited. This is why some writers find narrative prose more freeing and easier to compose. Over time, however, seasoned fiction authors will find themselves better able to fluidly switch between the two styles.
The Bottom Line
Narrative prose and short stories are very much alike, much more so than they are different. Each one can be used for a variety of storytelling, and which you should use simply depends upon the plot that you've come up with. In the case of nonfiction writing, stick with narrative prose rather than a short story.