In visual branding, the logo is indeed a necessary component. Branding is basically to be done within a company to promote a common culture or company philosophy. Everything from documents, office supplies, and other forms of internal communication can be designed to combine your company with your single message through visual branding.
Branding can also be used around a particular product or service. Consumers often recognize products and services more than the company that produces them because they relate to them more. Many elements of a product can be designed for its own brand from the user interface like logo, marketing promotion, packaging, product description to the website.