There are 32 ways to write a story, and I’ve used every one, but there’s only one plot: things are not what they seem.
– Jim Thompson.
Anthony Burgess was somewhat more stringent: he put the number of possible plots at about five.
So what distinguishes one plot from another? Or, to put that question more specifically, if two writers write the same plot, how if at all will those stories differ?
In fact, no two stories can be written exactly alike, and one of the reasons for this is the writer’s style. (“The most interesting story is always the story of the writer’s style,” said Nabokov.)
Styles are more diverse than fingerprints, and how the writer tells a story discloses exactly how that writer thinks.
Stories consist of several elements, the most fundamental of which is plot — plot being the skeleton upon which the meat of the story (characters, theme, descriptions) all hang — and ultimately what determines the differences in stories, even those with similar plots, is the depth of style, the depth of theme, and the seriousness of the approach.
Literature, for example, is distinguished from popular fiction by the seriousness of its themes and by how well the writer not only grasps but also conveys those themes.
In essence, literature conveys the importance of human life.
Plot is the means by which this is done.
There can be good plots with shallow themes (certain soap operas, for instance), and there can be good themes with poor plots (like the novel Light Years, by James Salter). But in either case, a theme cannot be clearly or convincingly conveyed without a good plot and a strong writing style.