Drywall (also called gypsum board, wallboard, or Sheetrock—a brand name) is the standard material for interior walls and ceilings in modern construction. It consists of gypsum plite sandwiched between paper facings, creating flat surfaces ready for painting or finishing. Drywall replaced the labour-intensive plaster and lath method, dramatically speeding construction. Standard drywall comes in 4-foot-wide sheets of various lengths and thicknesses. Specialized types include moisture-resistant drywall for bathrooms, fire-resistant drywall meeting building code requirements for certain walls and ceilings, and soundproof varieties for noise control. Installation involves screwing or nailing sheets to framing, then taping and mudding joints for smooth surfaces. Building codes specify drywall requirements based on fire separation needs between spaces like attached garages and living areas.