Coal is a hard, black colored rock-like substance. It is made up of carbon, hydrogen, nitrogen, and varying amount of sulphur. Coal was form as decomposition took place in the absence of oxygen and much of the hydrogen content of the matter was eroded away, leaving a material rich in carbon. The material was compressed over the years by sand and dirt, leaving the form of a carbon known as coal. The different types of coals are Anthracite, bituminous, lignite, peat, coke, and charcoal. Coal is mined out of the ground and used to produce energy