According to different uses, coal can be divided into injection coal, electric coal and coking coal. Coking coal can be divided into five categories: lean coal, coking coal, gas coal, fat coal and lignite. Coking coal is used to make coke and coke is used to make steel. The coal used in power plants is electric coal, which can also be said to be power coal. Under normal circumstances, coal that cannot be coked can be used as electric coal.