A logo is just a picture.
A brand gives meaning to the picture.
Marketing is the art of letting people know what a brand is about and making them care about it.
How a brand is experienced and perceived varies from person to person. You know marketing has accomplished its job when an audience believes and lives the story given to them.
For example, when you have the Nike checkmark on your t-shirt, you feel like you can do just about anything. Or when you see the Harvard logo on a someone’s sweater, you automatically perceive the wearer as smarter and more successful.
Without Nike, a checkmark would just be a checkmark.
Without Harvard (the school), the wordmark would just be another word.
While logos, brands, and marketing are related, they serve different purposes.