Ticket controller (transportation)

Imagine you want to go on a train or a bus ride. You need to have a ticket to show that you have paid for the ride. The person who check the tickets and make sure everyone has a valid one is called a ticket controller. They look at your ticket and make sure it is not expired or fake. If you don't have a ticket or it's not valid, they may ask you to give them money or get off the train or bus. The ticket controller's job is to make sure everyone on board has paid for their ride and to keep the transportation running smoothly.