Each elevator has a different capacity. The elevator's capacity means how many people can go by at a time. Instruction about the power of the elevator is always written outside the lift. If people more than its capacity enter the elevator, it will not move.
Inside the elevator, there were some buttons mentioned numbers on them. Floor numbers are mentioned on the buttons inside the elevator. The elevator will stop at the floor of the number you have pressed.
So, it is very easy to use the elevator. But use the elevator carefully!