Wood fuel is wood used as fuel. Burning wood is currently the largest use of energy derived from a solid. Wood fuel can be used for cooking and heating, and for fueling steam engines and steam turbines that generate electricity. Wood fuel may be available as firewood (ex: logs, bolts, blocks), charcoal, chips, sheets, pellets, and sawdust. The type of wood form used depends upon such as sources, quantity, quality, and application. Wood may be burned in a furnace, stove, or a fireplace. Wood is the most easily available form of fuel, requiring no tools in the case of picking up dead wood.
Today wood pellets are becoming very popular to use for heat. Instead of using logs, these pellets are made with sawdust and woodchips. It is really using all parts of cut wood. These pellets are squeezed into a small pencil sized round shapes that are then cut into smaller pieces. These small pellets make storing and handling much easier.
Citations "Wood pellet." Wikipedia. 11 Jan 2009