Heavy industry, group of companies, or productive organizations that produce or supply goods, services, or sources of income.In economics, industries are generally classified into primary, secondary, tertiary, and quaternary; Secondary industries are further classified as heavy and light.Primary industryThis sector of a nation's economy includes agriculture, forestry, fishing, mining, quarrying, and mineral extraction.It can be divided into two categories: genetic industry, including the production of raw materials that can be increased through human intervention in the production process; and extractive industry, including the production of exhaustible raw materials that cannot be increased by cultivation.Genetic industries include agriculture, forestry, and livestock, and fishing, all of which are subject to the scientific and technological improvement of renewable resources.Extractive industries include mineral extraction, stone mining, and mineral fuel extraction.The primary industry tends to dominate the economies of underdeveloped and developing nations, but as secondary and tertiary industries develop, their share in economic output tends to decline.Secondary industryThis sector, also called the manufacturing industry, takes the raw materials supplied by primary industries and processes them into consumer goods, or also processes goods that other secondary industries have transformed into products, or builds capital goods used to make consumer goods and I do not consume.hydroelectric industries) as well as the construction industry.Secondary industry can be divided into the heavy or large-scale industry and light or small-scale industry.hydroelectric.Light or small-scale, the industry can be characterized by non-durability of manufactured products and less capital investment in plant and equipment, and can involve non-standard products, such as custom or craftwork.