At the base of the windmill, you can see a pump-jack, pumping oil from deeper underground. The oil will be made into fuel, which powers the tractors and farm machinery necessary to plant, cultivate, and harvest the cotton. Everything works together to produce the crop.
The best stories are a little like this field. The main crop is the plot, driving the story along. But like dry-land farming, without the irrigation of well-developed characters the plot would wither and die. Strong characters are as crucial to a story as water is to a crop.
Far overhead, the breezes of the story drive the theme, the overarching feel of the story. Whether it's about the power of love or the misery of greed, the theme is the "lesson" we take from the story. Did you know windmills automatically shut down when the wind blows too hard? Theme is like that. It works best when it's a subtle breeze, not a hurricane.
And underneath it all, the author's voice produces the energy to plant the crop and nurture it. Humor, plot twists, juxtaposition: all the things that make a story special come from the reservoir of the author's personality and life experience.
All together, these forces add up to more than the sum of their parts. That's what produces a good crop, and what produces a good story.