Why is iron and steel industry called the basic industry?

Why is iron and steel industry called the basic industry? What are the problems faced by this industry?

Iron and steel industry is known as the basic industry because all the other industries (heavy, medium and light) depend on it for their machinery.
Problems faced by this industry are
(i) High cost
(ii) Limited availability of coking coal
(iii) Low productivity of labour
(iv) Irregular supply of energy
(v) Poor infrastructure