This may not seem an important question. After all, if you've written a novel it'll have hundreds of pages of your inspiring prose about people talking and stuff happening. But the thing is, people talking and stuff happening does not necessarily a story make no matter how inspiring the prose is. There are numerous definitions of what a story actually is, but the one I like best is that a story is a tale in which a likeable character achieves a worthwhile goal against impossible odds by his or her own efforts. There are exceptions, but nine times out of ten tales that follows this definition will work as a story and equally, nine times out of town tales that don't follow this format will not work.
There are four elements to this definition, the first of which is the most obvious: that a story must feature a likeable character. By likeable it's not essential to ensure your main character is as pure-hearted as fresh snow because, let's face it, people like that are annoying. But he/she should have something about them that makes the reader want to find out what happens to them. I mean, if your hero picks his nose, lets old ladies cross the road on their own and doesn't like dogs, who would want to waste their time with him?
I write westerns and in this genre it's not hard to make characters likeable while it's also not hard to make them flawed. Westerns detail a tough time where survival was a battle against man, terrain, climate. Anyone who can survive such times is admirable and worth spending time with, but equally survival calls for those people to do things that are unacceptable today. So for example my Avalon westerns follow my series character Fergal O'Brien, a snake-oil seller who is always eager to make a fast buck. He's cowardly, devious, sneaky, but he's never killed anyone and deep, deep down he's a decent man making his way in the world.
The second element of the definition is that your main character should have a goal. If they don't want to achieve something, there's no reason for the reader to read on to find out if they succeed. In westerns there's plenty of options such as finding the man who shot your pa, defending your land against the greedy rancher, tracking down those pesky bank robbers. But this goal can be a large one or a small one. In my The Finest Frontier Town in the West a whole town's fate was at stake and in The Treasure of Saint Woody Fergal's goal was to open a box. The important thing is that there is a goal, and ideally that it's an interesting one.
Thirdly there must be problems to stop your character achieving his goal, and they must be big ones. If your hero is a fast draw gunslinger who can shoot up every man who stands before him, the reader won't feel any tension. So give your hero an opponent who can draw even faster than he can. Then give his opponent five like-minded friends, break your hero's gun hand, tie him up in a burning saloon with a barrel of gunpowder dangling from the ceiling and a rattlesnake stuffed down his pants. Those problems must feel insurmountable, ideally to the extent that you as the writer have no idea how to solve them. In The Flying Wagon Fergal had 24 hours to learn how to fly. As there weren't many flying machines in the Wild West this was clearly an impossible problem and it was one I enjoyed solving.
Finally the hero must resolve the problems on his own without anyone intervening and making life easy for him. Westerns have the most well-known transgression of this rule when the cavalry rides over the hill to save the day. But I'd suggest that having the hero enjoy a whiskey in the saloon while someone else walks out on to that windswept street to face the bad guy at high noon is unlikely to please the reader.
So that is my basic rule for what a story is, and it's one I apply to everything I write. I try to make my hero likeable. I give him a goal. I give him problems. And then I force him to solve them. My next Avalon Western is The Miracle of Santa Maria, which is published next month. It again features the, hopefully, likeable Fergal O'Brien. This time he has the worthwhile goal of saving a young nun who has fallen into a coma. To save her he has to defeat a single-minded bishop, pesky bank robbers, a serial killing box, a sword-wielding actor and the worst joke I've ever committed to print. To find out if he succeeds by his own efforts, you'll have to read it!