A vendor is someone (person, business, organization) who supplies goods or services to another business. Office supplies can be purchased from vendors as well as accounting services.
Vendor Extended Definition
In the course of operating a business, services, and products may be needed that the business is not able to provide on its own. Vendors are the individuals or businesses who provide these items and services. They generally send an invoice for their services and set their own payment terms. Vendors are not employees of a business; they are separate entities.