Escalator

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 are used around the world in places where lifts would be impractical. Principal areas of usage include department stores,shopping malls, airports, transit systems (railway/railroad stations),convention centers, hotels, arenas, stadiums and pub