Biomass is a renewable fuel source that is derived from organic matter such as plants and animals. It is a form of energy that can be used to generate electricity, heat, and transportation fuels. Biomass is considered to be a sustainable energy source because it is renewable and does not produce greenhouse gases when burned. Additionally, biomass can be used to create biofuels, which are liquid fuels made from plant materials. Biofuels are becoming increasingly popular as an alternative to fossil fuels due to their environmental benefits.