The document discusses the development and importance of Computer Reservation Systems (CRS) and Global Distribution Systems (GDS) in the tourism industry, highlighting their functions, history, and evolution. It explains how CRS originated for airlines and expanded to various tourism sectors, leading to the formation of GDS that integrates multiple travel services for user convenience. The text also addresses the challenges presented by big data in the travel distribution chain and the necessity for regulatory frameworks to ensure fair competition and consumer choice.