What is included in your cruise purchase price? Because cruising is so different from other forms of travel, most new cruisers are surprised with how much is included. Each cruise line is slightly different, but there are some things that are always free on every cruise line.
Most important, most food is free. At the very least there will be a formal dining room that is completely free for all three meals, a buffet that serves all three meals and usually some snacks, and usually some sort of free food that's available twenty-four hours a day, but is probably not as good as the other food. Some ships, especially larger ones, will have additional free options like pizzerias and poolside burger restaurants. Most ships will also have specialty restaurants that you pay a fixed cover charge for, ranging from $10-40 or so. These are 100% optional and many cruisers never eat at them. Room service is also free but sometimes has a small flat delivery fee, which is usually waived for basic breakfasts.
The dining room will have a selection of 4-5 entrees that rotate every day, a similar number of appetizers, at least one soup and salad, as well as standards that are always available (salmon, chicken, steak, etc). You can order as many things from the menu as you like. It's not uncommon for people to have 2-3 appetizers as well as 2 entrees. The buffet will have a huge variety of options, usually including some Indian food as well as Chinese food. You do not tip at any of these restaraunts — service is included in the daily $10-13 flat gratuity that covers your cabin steward as well.
Beverages such as water, tea, coffee, and juice are free. Alcohol and soda cost extra and can be purchased individually or in packages, and are tipped either per-drink or flat rate if you buy a package.
In short, you will have access to more high-quality free food than you could possibly eat, but can also spend more money on food if you want to splurge.
Use of most facilities and entertainment is also included. This includes pools, decks, shows in the theater, the library, many events like karaoke and musical performances, dancing, the gym, and a lot more. Most ships have other activities that come with an upcharge like special fitness classes, go-karts, or spa services. Activities like rock climbing, ice skating, and mini golf tend to be free, but it varies from ship to ship. In general Royal Caribbean and Carnival don't charge for these activities as often as other cruise lines. All shows, including high-quality broadway shows are free.
Internet always costs money, but is fast and available for (relatively high) flat rates as well as per minute. Alcohol almost always costs money, but some Norwegian cruises include it for free. Shore excursions always cost money, though you can find your own fun on shore for free.
Most new cruisers are surprised at just how much is included on a cruise ship. If you don't drink or pay for shore excursions, it's quite possible to cruise for weeks without paying anything other than the flat-rate tips.