A part of a business's message that distinguishes it from all its competitors

is referred to as what?

Answer: Brand.

Explanation:

A brand usually a logo, name, word or sentence or the comnbination is a company's valuable assets that distinguishes its their product from its competitors. Overtime, A Brand which proves credibility will promote the company's worth and value and endear potential buyers to the benefit its owners and shareholders. A brand becomes a trademark when legal protection is conferred on it.