An Escalator is a type of vertical transportation in the form of a moving staircase which carries people between floors of a building. It consists of a motor-driven chain of individually linked steps on a track which cycle on a pair of tracks which keep them horizontal.

Escalators have the capacity to move large numbers of people. They can be placed in the same physical space as a staircase. They have no waiting interval (except during very heavy traffic). They can be used to guide people toward main exits or special exhibits. They may be weatherproofed for outdoor use. A non-functional escalator can function as a normal staircase, whereas many other methods of transport become useless when they break down or lose power.