What is coal composed of, and how do humans use it?

coal contains Carbon, hydrogen sulfur, oxygen and nitrogen.

We use it as a fuel in power plants.industrial furnaces.domestic cooking etc. It is mostly used in huge boilers to make steam and used for electrical power generation Olden times team engines and steam loco motives were using coal.. some type of good coal is used in blast furnace to make steel. In some industry coal is heated and concerted to gas which is used as fuel.