Inside cabins: These cabins are usually the lowest price. Typically they will have twin beds that convert to a queen size, a private bath with a shower, a closet for hanging clothes, a dresser and a television. These cabins do not have a window to let natural light in. To help give the occupants an impression of having a view, some inside cabins have a virtual view. That means there is a large screen that displays outside views. Expect to pay $100 to $200 a night for an inside cabin.
Inside cabins with no views at all are typically the smallest, cheapest cabins onboard. They are great options for budget-minded travelers who do not intend to spend a lot of time in their stateroom, or who want to sleep all day in absolute pitch dark. They are less ideal for cruisers prone to seasickness, those who need natural light and groups who require a lot of in-cabin space. Not everyone will be happy in an inside cabin; it is worth upgrading if the lack of light will put a damper on your vacation.
Having a personal butler can be a wonderfully pampering experience, and some cruise lines include the butler service as part of your fare when you select a suite or "concierge level" cabin. Look carefully at the difference in the cruise fare, and decide if it is really worth it. Beyond that, look at the services that are offered; some cruise line butlers really do provide extra value. For instance, some can bring you room service from hard-to-get-into alternative restaurants, refill your mini-bar to personal specifications, and serve in-cabin meals course-by-course. Butlers can also unpack and repack your bags, draw rose-petal baths and assist you in preparing in-suite cocktail parties.
Exception: Royal Caribbean and other cruise lines will also use sub categories to distinquish between how many occupants the cabin will sleep. Therefore a cabin that can sleep up to 4 people will be a different sub category from a cabin that sleeps only 2 people.