Which industry is often referred to as the backbone of modern industry and why?

The iron and steel industry is a primary or feeder industry as its products are used by other industries as raw materials. Steel is obtained from iron ore. It is characterized by toughness but high malleability which allows it to be shaped, cut or made into wires. It can be turned into special alloys with the addition of other metals like aluminium, nickel and copper which increases its durability and the ability to withstand rust. These characteristics of steel has made it one of the most important raw materials in the modern world. Most of the commodities starting from basic safety pins to large ships and automobiles are made from steel. Steel is not only used in farming in the form of machinery, but also in urban areas where large buildings have steel frameworks. Thus, the importance of the iron and steel industry has caused it to be referred to as the backbone of the modern industry.