In a nutshell, a brand is the way in which your customer perceives you.

Branding is not just a logo or your colors, it is how you talk in social media as well. Branding is the face and personality of your company. While creating a strong brand, consistency is key. You should always use the same style of speaking, and use your (soon to be) well known imagery.
Putting effort in branding attracts customers and gives them reason to trust you and your brand.