With the farm as the centre, agribusiness is that sector of the economy that includes all firms, agencies and institutions that provide inputs to the farm and procure commodities from the farm for processing and distribution to the consumer. Traditionally, agribusiness focused on farm inputs (ie, supplies such as farm machinery, feed, pesticides) and services (eg, financial institutions). The modern definition includes firms that buy raw farm commodities (eg, milk, hogs, grain, oilseeds) and process and distribute the wide range of resulting products through numerous channels to domestic and foreign consumers. Examples include firms involved in meat packing, flour and canning companies and retail food stores.

Agribusiness differs from other sectors of the economy because of the seasonality of crop and livestock production and, of course, weather. Many specialized institutions, such as Agricultural Marketing Boards and specialized government agencies (eg, Canadian Livestock Feed Board), play a role in controlling and directing the system. The many transactions surrounding the world's precarious food balance make it likely that the agribusiness sector of the Agriculture and Food system will continue to expand. See also Agricultural Economics.