A GDS flight booking system is a computer reservation system that acts as a single interface for viewing airline schedules, booking airline seats, and issuing airline tickets. Global travel companies are going for online airline reservation software because of 24/7 availability and real-time bookings. An airline reservation system is a web-based booking engine that is linked to global GDS systems like Amadeus, Galileo, and Sabre, which consolidates data from all airlines.