Yeah, if you go to a general US grocery store and see something described as a “yam” it’s going to be a sweet-potato, usually a larger or starchier variety.
Ube is a Dioscorea yam native to Asia. It’s closely related to the African yam. Most of this family of plants are big terrestrial vines that can live in somewhat dry places.
Taro, or kalo in Hawaiian, is from a different family of plants. It’s related to the peace lily. Most of this family of plants live in aquatic or marshy places.