During a production process, a product is created that is unintended, but still has positive value or is useful. That unintended product is the byproduct. Usually, the byproduct can be used for useful purposes.

Bio-industry

Examples of byproducts are often found in agriculture and the food industry. For example, not all the meat from a pig can be used in a pig slaughterhouse, and remains such as intestines, bones, hair, and blood are left over. These remains can be processed into animal meal or used as fertilizer.