If you own a business big or small. It's everything. Sure it's the logo. It is definitely the logo, but that is just the start of your brand. It's the specific colors not just red or light blue, but the exact Pantone swatches, the CMYK and RGB formulas to match. It's the mission statement you live and breathe by. It's how you package your goods and services, it's how you answer the phone, it's in your email signature, your tweets, the sign on the door, the tags on your goods, the thank you notes, email newsletters, it's the cards you hand out at those uncomfortable networking mixers, the carpet, the tile in the company workroom, the soap in the bathroom (be honest, you love it when a business has great smelling soap and you walk around smelling your hands like Mary Katherine Gallagher until it wears off).