It refers to the system of pipes, fixtures, and other apparatuses used for the distribution and disposal of water and the heating and cooling of buildings. A plumber specializes in installing, repairing, and maintaining systems. They are responsible for fixing leaks, unclogging drains, installing broilers and garbage disposals, and ensuring the proper functioning of toilets, sinks, and showers. Contractors also play a crucial role in emergencies, providing immediate solutions to burst pipes and sewer backups.