Most tours include all sightseeing. On a cruise, when you are in a port, shore excursions can add significantly to the cruise price. You can explore on your own, but unlike on a tour, you will have to organize transportation and pay for admission to museums or tourist attractions.
On a cruise, all meals are included. Some cruise lines have more exclusive restaurants that charge extra, but you can eat every meal for the cruise price. On tour packages, some lunches and dinners are usually not included so you can decide where to eat--but you have to pay for these meals. Read the fine print carefully.
On a tour, you can get more personalized attention, since even large tours are nowhere near the size of large cruise ships. A tour company like Perillo, which specializes in tours of Italy, caps its groups at 40; on a ship, you can have over 2,000 fellow passengers.
