What is the difference between a profession and a business?

A profession is a line of work, such as the medical profession, the accounting profession, etc. A person working in a profession might have his or her own business, or might be working for another person's business. A business is a company, it is an organizational structure for some commercial or profitable purpose. For example, a store is a type of business. If you work in a store, you are in the retail sales profession.