If you tend to get seasick, cabin location is really important. It is a question of engineering, really. The lower and more central you are in a ship, the less roll and sway you will feel. Even if you choose a balconied stateroom, choose the lowest level and the most midship one you can find. The higher decks and cabins at the very front (forward) or back (aft) of the ship will rock and roll the most.
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.
Oceanview cabins: These cabins are like inside cabins but usually have a port hole or window. A window is much more desirable than a porthole because the porthole can be difficult to look through. Windows will vary in size and some cabins will even have full floor to ceiling windows. Most window sizes for oceanview cabins are about 4 feet by 3 feet. Be sure to read the cabin description carefully to determine if there is a different type of window. Windows can not be opened. Expect to pay $150 to $250 a night for an oceanview.
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.
carnival cruise room layout
carnival cruise interior rooms
stateroom on a cruise ship