The term "airline tickets" refers to a document that is issued by an airline or travel agency, which authorizes the holder to board and fly on a specific flight. It serves as proof of purchase for a passenger's seat on the plane, indicating their departure date, time, originating city, destination, and other relevant details such as class of service (economy, business, first-class) or type of ticket (round trip, one way). Airline tickets are usually purchased through travel agents or directly from airlines, either online or in person. The cost of the ticket depends on various factors like distance, demand for seats, time of booking and other promotions offered by the airline.