Cruise lines are companies that operate cruise ships. Carnival Corporation & plc, the world’s largest cruise ship corporation, operates nine cruise lines globally with four headquartered in the United States. These four U.S.-headquartered cruise lines represent Carnival Corporation & plc’s North American segment: Holland America Line, Carnival Cruise Lines, Princess Cruises, and Seabourn Cruise Line. As the example of Carnival Corporation & plc’s North,American market illustrates, cruise lines operate in geographical segments, each segment consisting of its own unique branding. This branding schema is tailored to fit unique socioeconomic markers of these geographical segments. Cruise lines function directly with the consumer, the cruise ship tourist, in selling cruise ship vacations as well as ensuring customer loyalty with each brand of cruise line. Cruise lines not only represent the method of tourist transport in cruise ship tourism but also the economic foundation of this industry and genre of tourism.
Vassallo-Oby, Christine, "Cruise Ships" (2017). The SAGE International Encyclopedia of Travel and Tourism. (309-312)