A fruit is the mature ovary of a seed plant, usually developed from a flower. Fruits have seeds so they further the reproductive cycle. A vegetable is a plant or that part of a plant which is edible, and does not necessarily have a role in the plant's reproductive cycle. While most vegetables and fruits are easy to distinguish and classify, some are still ambiguous as to whether they are a vegetable or a fruit. Tomatoes, olives and avocados are often considered vegetables, but are actually fruits.