Sheet Good

Sheet good is the umbrella term for manufactured flat panel material sold in standard sheet sizes (4'x8' being the default) -- plywood, MDF, particleboard, and hardboard are all sheet goods, as distinct from solid lumber milled from a single piece of a tree. Each sheet good trades off cost, weight, strength, screw-holding ability, and surface quality differently, which is why cabinet work often mixes several within one project -- plywood for structural carcase panels, MDF for a painted door, hardboard for a drawer bottom -- rather than using just one throughout.