Business-to-business (B2B or, in some countries, BtoB) refers to a situation where one business makes a commercial transaction with another. This typically occurs when:

• A business is sourcing materials for their production process (e.g. a food manufacturer purchasing salt).
• A business needs the services of another for operational reasons (e.g. a food manufacturer employing an accountancy firm to audit their finances).
• A business re-sells goods and services produced by others (e.g. a retailer buying the end product from the food manufacturer).