Coal is a combustible rock that is formed from the remains of plants and trees that lived millions of years ago. It is a fossil fuel that is mined from underground deposits and is commonly used as a source of energy for electricity generation and industrial processes. Coal is a black or dark brown sedimentary rock that is made up primarily of carbon, along with small amounts of other elements like sulfur, hydrogen, and oxygen. The burning of coal releases harmful pollutants into the atmosphere, contributing to air pollution and greenhouse gas emissions. Despite its negative environmental impacts, coal remains a significant source of energy in many parts of the world due to its abundance and relatively low cost.