Ans - There are Four Types of Coals. They are:Anthracite - It is hard, brittle, and black lustrous coal. This coal is often called as hard coal as it contains a high percentage of fixed carbon and a low percent of volatile matter.Bituminous - This is a middle-ranked coal. This has a high heating value and is used in electricity generation and sometimes steel making. Bituminous coal is blocky and it appears shiny and smooth but actually has thin, shiny, alternating, and dull layers.Subbituminous - This coal is black in colour and is dull. It has low to moderate heating values.Lignite - Lignite coal is brown coal. It is the lowest grade coal. This has the least concentration of carbon. Lignite coal has a low heating value and high moisture content.