Coal is world’s most abundant fossil fuel formed from the decomposition of organic materials, plants, vegetation that accumulated in swamps to great depths. With burial, the plant material was subjected to high temperatures and pressures over millions of years. This caused physical and chemical changes in the vegetation, transforming it into peat and then into coal. While being transformed from organic matter (peat) into coal, it underwent various stages like formation of lignite or ‘brown coal ‘, which is the lowest quality of coal, to sub bituminous to bituminous and then anthracite, which is the highest quality and hardest coal. High-rank coals are high in carbon and therefore heat value, but low in hydrogen and oxygen. Low-rank coals are low in carbon but high in hydrogen and oxygen content. In addition to carbon, coals contain hydrogen, oxygen, nitrogen and varying amounts of sulphur. Use of Coal Coal has many important uses worldwide. The most significant uses are in electricity generation. Not only does coal provide electricity, it is also an essential fuel for steel and cement production. Other important users of coal include paper manufacturers, chemical and pharmaceutical industries.