Airline distribution is just another way to saying selling of commercial airline tickets. Distribution is the lifeblood of the airline industry. That's why it has multiple ways of selling tickets -- some direct and others through outside distributors. Mostly, being a distributor means being some form of travel agent or agency, although there are some choices and distinctions based on different sales models.
Enroll as an independent contractor at an existing travel agency. This allows you to have your own business under the umbrella of an existing company which already has reservations systems subscriptions, equipment and space. You can avoid many of the hassles of setting up an independent agency of your own by either paying rent and fees or splitting your commissions.
Set up your own travel agency and either link to a host agency or acquire a license to issue your own tickets, instead of becoming a contractor. If you decide on a host agency, you will need an agreement with a travel agency. This usually involves a commission-splitting arrangement for access to their ticket issuing systems.
Apply for accreditation with the International Airlines Travel Agent Network (IATAN) which is owned and operated by the International Airline Transportation Association (IATA). IATA sets standards and methods of cooperation among its 230 member airlines. It founded IATAN as a way to accredit travel agents and distributors who understand IATA ticketing rules, standards and procedures. IATAN membership is not required to be a travel agent, but it is necessary to gain access to ticket issuance and other advanced forms of airline distribution.
Purchase a subscription to one of the major airline global delivery systems such as Amadeus, Sabre or Gailleo to be able to access airline and ticket information. If you pay additional fees and hold an IATA membership, you can gain license to issue your own airline tickets. But whether this is financially advantageous for you or not depends on your sales volume and on whether you want to become a host agency.
Use your global delivery system or GDS to directly purchase discount tickets that airlines are trying to unload and then resell them if you want to enter the world of ticket consolidation. Airlines use consolidators to ensure that they don't have any unsold seats for their flights. Because the consolidation agency is taking a risk by purchasing blocks of tickets in advance, airlines give steep discounts. In turn, consolidators sell the cheap tickets at a markup, but usually below the price at which the ticket is retailed.