A wood chipper is a machine that is used to break down wood into small pieces. The basic structure of a wood chipper includes a hopper, a drum or disc with cutting blades, and a discharge chute. The hopper is where the wood is fed into the machine, and the drum or disc rotates at high speed to cut the wood into small chips. The chips are then discharged through the chute. Some wood chippers have additional features, such as a self-feeding mechanism or an adjustable cutting blade, which can help to optimize the performance of the machine.