A cruise line is a company that operates cruise ships, providing vacation experiences on the water. These ships travel to various destinations, offering passengers a range of amenities, entertainment, and dining options. Popular cruise lines include Carnival Cruise Line, Royal Caribbean, and Norwegian Cruise Line. Cruise lines typically offer different types of itineraries, from short weekend trips to longer voyages that explore multiple countries. Passengers can enjoy activities such as swimming, dining, and live shows while traveling. Many cruise lines also provide themed cruises, catering to specific interests like family vacations or adventure travel.