A brand is a promise of satisfaction. It is a sign, a metaphor operating as an unwritten contract between a manufacturer and a consumer, a seller and a buyer, a performer and an audience, an environment and those who inhabit it, an event and those who experience it.
The consumer, buyer, audience, inhabitant, and "experiencer" (all customers) form their own feelings about what a brand means; but they can be influenced—more than most realize—by the advertising and publicity of the manufaacturer, seller, performer, environment, or event (all producers).
Branding is the process of continuous struggle between producers and customers to define that promise and meaning. To paraphrase Karl Marx, people make their own decisions about who to be, how to live, and what to buy, but under circumstances shaped by brands' advertising, marketing, and publicity.