How do elevators work?

An elevator moves things or people from one level to another, and is important to tall structures like skyscrapers. The car of an elevator, in which people ride, is attached to guard rails inside a tall, empty space called a shaft. It is moved by a steel cable that is attached to a large weight that counterbalances it. An electric motor raises and lowers the cable, changing the positions of the car and weight as the elevator moves from floor to floor. (Usually posted inside an elevator are numbers that indicate the car’s weight limit; an elevator motor cannot do its job if a car is a lot heavier than the weight that balances it.)