Norwegian Cruise Line Holdings oversees three brands: Norwegian, Oceania, and Regent Seven Seas.Brittany Chang/Business InsiderNorwegian Cruise Line Holdings operates three brands: Norwegian, Regent Seven Seas, and Oceania.The companies target different guests, from families with young children to wealthy older travelers.Here's how the three cruise lines compare and how to pick the best one for your vacation.Norwegian Cruise Line Holdings is best known for its eponymous brand's exciting, family-friendly ships.However, 40% of the cruise giant's vessels — specifically those of its premium Oceania and ultra-luxury Regent Seven Seas cruise lines — are devoid of waterslides and virtual reality arcades.Instead, the two high-end brands offer caviar-topped meals, calm pool decks, and upscale afternoon tea.With such a diverse fleet, it's no wonder the cruise giant is having a banner year.