The heart of any story is always going to be conflict. Somebody wants something, and someone or something stands in their way.
The object of a character's desire can be just about anything. A person in particular, love in general, a career goal, some sort of treasure, revenge, power, money - all sorts of things can function in this role. It can be a positive or a negative thing. That will depend on which character wants it.
It could be that your hero wants something and the villain is standing in their way. Or you could turn it around the other way and have a villain who wants something - something that will make them powerful and give them the ability to hurt people, for instance - and the only thing standing in their way is the hero. Either way you set up your plot it comes down to: somebody wants something, and someone or something stands in their way.
But does a story really need conflict, you might wonder. The short answer: YES. Think about the last book you read, or movie you watched. Did the plot revolve around some sort of conflict? Of course it did. Even romance novels. Especially romance novels. There's always some reason why that couple can't get together right away, something that keeps them apart for three hundred pages. Maybe it's something tangible, but a lot of times in romance novels its an internal conflict. One or both of the characters has been hurt in the past and they're trying desperately to protect their heart and not fall in love. You know they'll get their Happily Ever After by the last page but in the meantime the author keeps you on the ropes with that conflict and the tension it creates.
And that is why stories need conflict: tension. There's got to be something at stake for these characters, otherwise there's not much point. With nothing at stake you get a boring story and boring characters that readers don't feel invested in.
Conflict and tension are things that are not welcome in real life, but in fiction they are essential. They are your starting point. When I begin outlining, or even just random notes about a new story idea, the first big thing I have to figure out is what's the conflict, what's at stake? A great deal of the rest of the story and characterization flow from that.
And for something without an conflict or tension - writer/blogger Carolyn Arnold was nice enough to pass along to us the Lovely Blog Award. From all of us here at Write Club, thanks for the award Carolyn!