Fruits bear seeds developing from the ovaries of a plant and potatoes are tubers and do not produce seeds which makes it clear that they cannot be classified as fruits. Potatoes are stem vegetables that are grown on stolons found underground. Some experts classify them as a form of starch due to their starchy nature. Besides being a common protein source, they are also very high in carbohydrates and can be used in place of rice and bread. Due to their function as starch, they are nutritionally considered as a starchy carb. If you want some more information or have any questions then let me know.
Source : potatoes
Source : potatoes