A flight is a service provided by an airline to transport customers by aircraft from a departure location to a destination on a certain date and at a certain time.

A flight connection is an offer by a travel agency for a direct or an indirect flight. An indirect flight consists of multiple route segments.

Note: Not every travel agency has to have all possible flight connections in its system.

A flight booking is a seat reservation for a flight with an airline.

A flight trip consists of an outbound flight and, optionally, a return flight. Booking a flight trip constitutes a binding contract between the flight customer and the travel agency. A flight trip can be booked for more than one passenger.

A travel agency is an airline partner. Airlines can offer their flights and sell tickets through a travel agency. Customers can book flight trips at a travel agency and, in doing so, buy tickets from airlines.