The way I explain what a “story” is is to contrast it with “plot.” The latter is easy to define; it’s a sequence of events. You can tell if a movie has a story by observing if it makes you want to watch it again. A plot can be interesting by itself, especially if it has a lot of twists and turns, as well as suspense and surprise, but if it has no story, you’d be bored the second time because there are no other redeeming qualities once you know what happens.
“Story” is the artistic substance. It resists reduction, so it’s impossible to articulate it clearly, which is why you can enjoy reading a great novel many times, even if you remember the plot. You take away something new every time. As a writer, it’s better not to articulate what your story is because doing so may result in a one-dimensional story. Once the audience gets it, it’s over.
“Story” motivates you to write, and it also motivates people to read, yet you don’t know why. And, it’s better that way. Writers’ challenge is to capture this je ne sais quoi that resists capturing. You cannot systematically plan a good story, even though you can plan a plot.
This definition of “story” can be applied to many things. For instance, some people may have an impressive list of accomplishments but no story. A business with a long list of products but no story. A product with a long list of features but no story.
A story must be self-evident; it must be shown, not said.