While both sweet potatoes and yams are tubers, there is a big difference between the two. Yams are starchier and drier than sweet potatoes, and they also have a different flavor. Candied yams are often made with brown sugar, butter, and cinnamon, while candied sweet potatoes usually just use sugar and spices. They are not the same thing, but in this case, they can be used somewhat interchangeably for a tasty side dish. You may even find different colored yams and sweet potatoes that add a unique look and flavor to the side dish.