If scenery is important to you, take a good look at your cruise itinerary before selecting your cabin, specifically if you are choosing an outside or balcony. On a roundtrip Caribbean cruise or a transatlantic crossing, for example, the side of the ship you are on does not really matter. If, on the other hand, you are doing a one-way sailing (such as a southbound Alaska cruise or a trip from Barcelona to Rome), you might want to consider choosing a cabin on the side of the ship that faces the land. Sometimes the views can be breathtaking, and you would not get those views from the cabins that face out to the open sea.
On many ships, basic inside and outside cabins are usually the same size, the difference being that one has a porthole or picture window to let in natural light. Balcony cabins can also be the same size as standard insides and outsides, with the addition of the outdoor space on the verandah; sometimes the interior space is larger. A basic cabin, regardless of category, is referred to as a "standard" unless there is something about it that makes it different (such as physical layout, being handicapped accessible or a designated family cabin). With minisuites on up, you get bigger and bigger indoor and outdoor spaces.
Pay attention to the unique cabin setups on your ship, as they are not all created equal. Disneys four cruise ships, for example, have large standard staterooms designed to accommodate families. Even inside cabins may have a sleeping section that can be curtained off from the living area along with a split bath system. (One bathroom has the shower/tub and sink, another a toilet and sink.) Carnival is also known for having larger-than-average standard cabins, while Silversea, Regent Seven Seas Cruises and Seabourn ships feature all-suite accommodations. Norwegian Epic cabins sport the "new wave" design, with curvy walls and separate rooms for showers and toilets; sinks are located in the main cabins. As mentioned earlier, cabins at the very front and back of a ship often have different layouts than the cookie-cutter cabins that run the length of the ship.
Very few ships actually have cabins dedicated to solo travelers. These will have sleeping space for one and can be quite small. The studio cabins on select Norwegian ships are the most famous example of this: The 100-square-foot staterooms each contain a full-size bed, nifty lighting effects and a large round window that looks out into the corridor. If you are a solo traveler, you will want to price out the cost of a solo cabin (usually somewhat higher than the double-occupancy rate of a similarly sized stateroom) compared to the cost of paying the single supplement (an extra fee tacked on if there are not two people in a cabin; the price can come out to as much as double the regular rate) for a standard cabin. And book early, as solo cabins sell out quickly.
stateroom on a cruise ship
stateroom vs cabin
cruise ship cabin photos