Cruise lines refer to companies that operate cruise ships and offer vacation packages that include transportation, accommodations, meals, entertainment, and other activities on board their vessels. These companies cater to a wide range of customers, from families looking for fun-filled adventures to couples seeking romantic getaways or seniors wanting relaxing retreats. The cruise lines industry has grown significantly over the years, with more than 40 major cruise lines operating worldwide and offering various itineraries that cater to different interests and budgets.