A pellet mill is like a magic machine that turns small pieces of wood or biomass into long, skinny, and uniform pellets that can be burned for energy. First, the wood or biomass material is fed into the mill and ground into tiny pieces. Then, these tiny pieces are packed tightly into a die, which is like a cookie cutter, but instead of cutting out cookie shapes, it shapes the pellets. The pellets are then extruded through the die using a roller, which compresses them and gives them their long, skinny shape. Finally, the pellets are cooled and dried, and they're ready to be used as fuel to heat homes, businesses, and even power plants. Just imagine it like playing with modeling clay!