A mango is classified as a fruit because it is the mature ovary of a flowering plant that typically contains seeds. Fruits are typically sweet, fleshy, and edible, which aligns with the characteristics of a mango. On the other hand, vegetables are usually the edible parts of plants that are not classified as fruits, such as roots, leaves, stems, or bulbs. Since a mango is not any of these, it falls under the category of fruit.