Final answer:
A by-product is a secondary product recovered during the manufacturing of a primary product. The secondary sector includes manufacturing, which processes raw materials, and the creation of by-products can contribute to economic growth.
Step-by-step explanation:
A by-product is a secondary product recovered in the course of manufacturing a primary product during a joint process. In the secondary sector of the economy, manufacturing transforms natural resources into finished products, which involves the processing of raw materials.
By-products may not be the main focus of the manufacturing process but can be an important source of additional revenue for a company. The presence of a strong secondary sector often leads to economic growth and job creation, although in recent decades, there has been a decline of manufacturing jobs in the United States, partly due to the relocation of jobs to countries with lower labor costs.