The answer to 'how does bathtub work' is that a bathtub is a large, basin-like container used for bathing. It is typically made of porcelain, fiberglass, or acrylic and is installed in a bathroom. Bathtubs have a drain at the bottom that allows water to flow out, and they may also have a faucet and showerhead for filling and rinsing. The tub is filled with water, and the user sits or reclines in the water to bathe.
Bathtubs can be freestanding or built into a bathroom's cabinetry or tiling. They come in a variety of sizes and shapes to fit different bathroom layouts and personal preferences. Some bathtubs also have additional features like jets or heating elements to provide a more spa-like experience.