It seems a simple question. But it's not.
It means many different things to people. For some it's using narrative thinking and storytelling techniques to define a brand.
Others define it as a mix of content marketing, brand journalism, and article writing. I've also heard it defined as the art of connecting the hearts and minds of customers to shared values and ideals.
They're all right to some degree but for me it goes deeper.
Story enables us to place and re-inforce a belief in the mind of our audience, that if combined with a great product or service can influence a future purchase decision.
Steve Jobs understood that. He knew the power of getting people to believe that they can change the world with the work they do using Apple products.