Common household plungers
A plunger is a common device used to release stoppages in plumbing. It consists of a rubber cup with an attached stick, usually made of wood. The cup is pushed down against the drain, and either pressed hard into the drain to force air in, or is pushed down until the rubber cup is flattened, then pulled out, causing a vacuum. The intent is to loosen or break up a clog, excessive material, or other blockage in a sink, toilet, bathtub, shower, etc.
When a plunger is ineffective, it is often supplemented by chemical drain opener, the use of a plumber's snake , or, if necessary, a plumber will be called at significant expense.