Flexi Says: Although both coal and charcoal are carbon, they form in different ways. Coal is a non-renewable fossil fuel that is made from plants and animals that lived hundreds of millions of years ago. As the plants and animals died, their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. However, charcoal is formed by the incomplete combustion of wood and it is a solid porous substance.