A plumber is a skilled tradesperson who specializes in installing, repairing, and maintaining systems that transport water, gas, and waste in residential and commercial buildings. They work with various materials, including pipes, fixtures, and fittings, to ensure that plumbing systems function properly and efficiently. Plumbers often respond to emergencies, such as leaks or clogs, and may also perform routine maintenance to prevent future issues. They must understand local building codes and safety regulations to ensure their work meets legal standards. Common tools used by plumbers include wrenches, pipe cutters, and augers.