A Global Distribution System is a B2B reservation network that connects travel suppliers (airlines, hotels, car rentals) to travel agents and corporate-travel management platforms. The three dominant GDSs are Amadeus, Sabre, and Travelport (which owns Galileo and Worldspan).
Hotels list inventory on GDS primarily for business-travel access — corporate-travel managers at Netflix, McKinsey, or Google use GDS-powered platforms (Concur, Navan, TripActions) to book rooms at negotiated corporate rates that don't appear on consumer-facing OTAs.
For leisure travel, GDS is less relevant than bed banks — the wholesale inventory traveling through GDS is mostly packaged with flights. But understanding GDS helps explain why corporate-rate tiers exist parallel to the wholesale/BAR distinction.