What is a plumbers snake:
The basic design of a plumber's snake consists of a long coiled wire attached to a crank. The crank is turned in a clockwise direction to slowly force the plumber's snake into the clogged pipeline. In some cases, a plumber's snake may actually pick items up as it moves, in which case they are removed from the coils of the wire when it is pulled out of the plumbing. In other instances, a plumber's snake breaks up the cause of the clog, allowing water to flow freely again, and snakes also break down the gunk inside of pipes as they flail around.
A small or short plumber's snake is cranked by hand. Others have motorized cranks, designed for penetrating large pipes with serious clogs. Motorized snakes should only be used by people who are experienced with them, as they can damage the plumbing or injure the user if he or she is not familiar with the workings of the snake.
Fancy plumber's snakes even come with cameras which allow the plumber to see what is going on. This can be useful when a clog seems intractable, or when a plumber wants to asses the general condition of a pipe. It can also be surprising, as an astounding assortment of things wind up down pipes, especially pipes shared by multiple households, as might be the case with an apartment building.