A boarding pass is a document provided by an airline that allows a passenger to enter the restricted area of an airport and board a specific flight. It contains important information such as the passenger's name, flight number, departure time, and gate number. Boarding passes can be issued in paper form or electronically on a mobile device. Passengers typically receive their boarding pass during check-in, which can be done online or at the airport. The boarding pass is scanned at the gate before boarding the aircraft, ensuring that only authorized individuals can access the airplane.