Your brand is the promise to the customer. It is the sum of their experiences and knowledge of your brand. Your customer defines it, but you can influence it. A brand is a shortcut in a customer's mind to understanding what you do and how you do it. It is the sum of experience and knowledge of your company positioning, your reputation.
Your logo is not your brand.
Your branding, or visual identity, is absolutely a component of your brand - it should be a visual translation, a reminder, of your brand promise and the experience, but it is not the sum of your brand.
You can influence your brand (the promise and the perception) through the triggers and levers of branding, of which visual identity is one lever. You can influence your brand through the language you use and the tone and personality you use when you write your ads and content. You can influence your brand through the channels you use to communicate and advertise.