In certain parts of the world, the terms "yams" and "sweet potatoes" are often used interchangeably, leading to some confusion about whether they can be substituted for each other. Technically, yams and sweet potatoes are distinct types of plants. Yams possess rough, dark brown, bark-like skin and are generally less sweet and more starchy than sweet potatoes. In contrast, sweet potatoes have smoother skin and yield a softer, sweeter flesh when cooked. As I don't frequently cook with yams, I cannot guarantee that the flavour and texture will be identical when substituting them in this mashed sweet potato recipe.