Yams and sweet potatoes are both root vegetables, and they look similar, but they are not the same. Yams are a starchy root vegetable that is native to Africa and Asia. They are cylindrical in shape, with dark, scaly skins. The flesh of a yam is starchier and drier than that of a sweet potato, and can range in color from white to purple.
Sweet potatoes, on the other hand, are a root vegetable native to Central and South America. They have a tapered shape and a smooth, thin skin. The flesh of a sweet potato can be white, yellow, orange, or purple. Sweet potatoes have a sweet, creamy taste and are moister than yams.