The Global Distribution System of the airlines is nothing but a centralized computerized
reservation platform which provides the information about and allows the booking of flights globally. These are the centralized repository of flight tickets which allow users to search, find and book air tickets on various airlines operating on a particular sector. The evolution of GDS has been through successive phases of development and initially, the system was used by individual airlines to provide automated booking systems for their own flights. Thereafter, there was also a demand by the agents for having the access to these systems so as to enable them to book air tickets for their passengers.
The GDS has been a useful tool for finding the inventory of seats on different airlines globally. It is used both by the airlines as well as by agencies to book the flights. Since some of the major distribution systems are the third party resources, there are charges associated with the buying of tickets from their listed inventories. It shall be noted that the early GDS was meant for flights but the systems are now also used for booking hotels and cabs as well. Further, GDS was developed in an era when the computers and internet were not developed and used for providing ecommerce facility on a large scale as is the case now. Therefore, these were very important sources of getting information on seats availability on various airlines.
The situation has undergone a change now since the airlines are now attracting customers to do the bookings right from their own websites. They are putting up less and less inventories on sale on the GDS systems since it means parting with their profits by paying commissions on sale of cheap air tickets. Further, the airlines and other travel product owners have been increasingly using the agencies for their seats distribution rather than putting these on the GDS.
It would be wrong to assess that the GDS system has outlived its utility and is still referred to in order to find the seats and do the flight booking. However, it is referred to only as a last resort measure to book air tickets. Different airlines make use of different GDS applications but there are moves on the part of airlines to wean away from the influence of GDS which makes them part with substantial sums of money as commission annually.