Passenger ticket is the contract of carriage between the airlines and the passenger. While traveling, passengers are required to keep passenger ticket(s) with you throughout your journey, as it is required for check-in and immigration purposes.
For traditional paper ticket, passenger must have your own ticket(s) with the valid flight coupon for a specific flight.
For eTicket, passenger should only bring a printed copy of eTicket Receipt of your own eTicket while traveling.