Botanically, a tomato is a fruit: the ovary, together with its seeds, of a flowering plant. However, the tomato has a much lower sugar content than other fruits, and is therefore not as sweet. Typically served as part of a salad or main course of a meal, rather than at dessert, it is considered a vegetable for most culinary purposes. One exception is that tomatoes are treated as a fruit in home canning practices: they are acidic enough to be processed in a water bath rather than a pressure cooker as "vegetables" require. Tomatoes are not the only foodstuff with this ambiguity: eggplants, cucumbers, and squashes of all kinds (such as zucchini and pumpkins) are all botanically fruits, yet cooked as vegetables.
This argument has had legal implications in the United States. In 1887, U.S. tariff laws that imposed a duty on vegetables, but not on fruits, caused the tomato's status to become a matter of legal importance. The U.S. Supreme Court settled the controversy on May 10, 1893, by declaring that the tomato is a vegetable, based on the popular definition that classifies vegetables by use, that they are generally served with dinner and not dessert