A supplier and a vendor are both entities that supply goods or services, but the term vendor can be used for both business-to-consumer (B2C) and business-to-business (B2B) sales relationships, while the term supplier is typically only used for B2B relationships. A vendor also differs from a supplier in that a vendor can be both a supplier and a manufacturer.
A B2B food vendor sells food to a restaurant so that it can be resold to the restaurant's customers, but a B2C vendor, such as a hot dog vendor, sells its products directly to consumers. A supplier typically only deals with other businesses, and it usually sells products wholesale to a company that eventually resells them at retail.
Both vendor and supplier refer to the entity that takes money for the supplies or services, and neither term refers exclusively to the manufacturer of the products. The person who pays the vendor or supplier is called the purchaser.
Vendors and suppliers do not just supply businesses with wholesale items. They also supply businesses with items that can be used to make an end product. For instance, a supplier could sell small parts to a car manufacturer or metal to a computer manufacturer.