This came up in another thread. sto·ry noun an account of imaginary or real people and events told for entertainment. "an adventure story" an account of past events in someone's life or in the evolution of something. "the story of modern farming" There are fiction stories, news stories, long stories, short stories. "Why is your news channel so sensational and biased?" "Well you tuned in for a story, didn't you?" I think at minimum there must be events (otherwise known as plot). The events could have happened in the past, present, or future. It could be one event, but something must happen or have happened. It also shouldn't be a ledger, rather, the events need to be framed in some form of meaningful (usually emotional) context in order to create entertainment. Sometimes the events themselves could be used to create that framing, but that's an atypical expository route. What do you expect from a story? What should it have, what's it better off having, and what does it not need? This discussion doesn't have to be limited to minimum definitions. Interested in what anyone has to add/contend about this or their own expectations and standards.
It could refer to an explanation of someone's unexpected behavior: "What's his story?" I use it most often to respond to someone's whiny tale of personal woe: "Eight billion people in the world - eight billion sad stories. Get over it."
I've seen numerous submission guidelines state that they want narratives with a clear beginning, middle, and end, so that's probably a good starting point. Once you drop some of that, you get into experimental territory, and people start disagreeing about whether you've written a "real story." Does the classic "baby shoes" 6-word story count as a story itself, or is it just a seed that lets you imagine the real story?
