The escalator, or moving stairs, you see in department stores, airports, and railway stations all work on the same principle, an endless belt moving around wheels.
The stairs are attached to two side belts or to one central belt, which is driven by electricity. The moving handrails on both sides of the escalator work the same way and are timed at the same speed as the steps.
At the top and bottom of the escalator, the steps fold flat for their trip underneath to reach the opposite end, where they open up and start again.
The same escalator can be used to run up or down, depending on the direction in which the belt is driven.
An escalator can be dangerous if one is wearing “crocs” flipflops or long or untied shoelaces that can get caught as the staircase is closing. It is good to remember that there is an emergency red button at the top and bottom of every flight of escalators. Anyone passing by, upon noticing someone in distress can press the button and the escalator will come to a full stop.