http://www.wisegeek.org/what-does-a-plumber-do.htm
A plumber installs and repairs pipes that are used to carry water, gas, sewage, and wastewater. These pipes are often collectively referred to as “plumbing.” They install and repair fixtures such as sinks, toilets and disposals. They also need to know health and safety codes, as well as basic carpentry to access pipes within walls.
