What goes inside a wall?

Inside a wall goes structural framing, insulation, and utilities that support building function. Typical residential wall interior contains vertical studs made of wood or metal that provide structural support, horizontal top and bottom plates, insulation such as fiberglass batts, cellulose, or spray foam between studs for thermal and acoustic insulation, electrical wiring that runs through drilled holes in studs connecting to outlets, switches, and fixtures, plumbing pipes for water supply and drainage in bathroom and kitchen walls, HVAC ducts in some walls, low voltage wiring for internet, cable, and phone, vapor barrier or moisture barrier to prevent condensation, fire blocking in certain walls for fire safety, and drywall or plasterboard on exterior of studs. In older homes, walls may contain lath and plaster, knob and tube wiring, or no insulation. Exterior walls also contain sheathing, house wrap, and siding. Essentially, inside wall is hollow cavity filled with structure, insulation, and utilities that make building functional.