We know what they are, we ride them all the time, but how to they work. They are build like stairs. Stairs for this very obese country are a problem, people don't like to use them because they don't want to do work. People do not like exerting a force to push themselves up the stairs a certain displacement to do work. They want the escalator to do it for them, they want to be pulled up. So you stand on a stair and have the escalator with it's belt of flatting stairs use it's tension to exert the force to move you up or down. So when the escalator is broken we all mone and gron because now we have to do our own work.