• Bathroom sinks are often simple white basins.modern sink image by nextrecord from Fotolia.com
  
  Sinks are a common sight in bathrooms and kitchens, and conveniently bring hot and cold water into the home for drinking and cleaning. While most of us take sinks for granted, they are actually composed of several different components that all must function together in order to provide a clean supply of water at the proper temperature and pressure. Regular maintenance will ensure that they continue to perform this essential function well.
  
  

Supply Lines

• Most sinks include two supply lines, one for hot water and one for cold water. The lines are created from a durable, flexible material and come through the well behind the sink or up through the base of the sink.
  
  

Faucets

• Sinks may have one or multiple faucets. Most often a sink has a single faucet with two handles, or sometimes two faucets--one each for hot and cold water. In either case, the faucet is held in place from below by a washer and nut. Water flows up and out through the faucet. A coupling nut, gasket and a rubber or ceramic cartridge prevents water from leaking out while still often allowing the faucet to pivot freely.
  
  

Basin

• The basin is the main section of the sink, catching water and providing the housing for many of the other components. Basins are most often made of plastic, metal or ceramic material. Decorative basins may feature a painted design or inlaid ceramic tiles. Other basins are integrated into the surrounding counter top. Bathroom sink basins may include drain holes near the top to allow water to drain away before the basin reaches the point of overflowing.
  
  

Drain

• The drain is located at the lowest point in the basin and serves as an outlet for water. In its simplest form the drain is a hole, but many drains include stoppers to allow you to hold water in the basin or a net to prevent solid objects from falling into the drain.
  
  

Tail Piece

• A sink's tail piece is a wide, rigid length of pipe that accepts drain water. It sits below the basin vertically, with its highest point attached to the drain via a gasket and its lower end attached to the P-trap with a fastener such as a friction ring or slip joint washer.
  
  

P-Trap

• The P-trap is a length of rigid pipe named for its resemblance to the letter P. It connects the tail piece to the flange where it enters the wall and allows water to drain into the plumbing and out of the home. The P-trap curves to catch objects that might fall into the drain and is a common site for build-ups of hair and debris that can slow a sink's draining.