Steam cleaners deep clean and sanitize various surfaces by using hot vapor to loosen dirt, grease, soap scum, and kill germs, making them great for kitchens (ovens, sinks, appliances), bathrooms (tile, grout, toilets), floors (tile, sealed hardwood), upholstery, mattresses, windows, and even clothes/drapes for deodorizing and de-wrinkling. They are versatile tools for chemical-free cleaning, effective on hard surfaces and fabrics, but require care on cold glass or electronics.