Indeed, they are all part of the Aroid family, but "pothos" is not the same as a philodendron. In fact, and this is where common names can get you into trouble, some plants that people call "split leaf philodendron" are not really philodendrons, either. I'd have to see a picture of the plant you refer to in order to be sure what it is. Some people call the Philodendron selloum a "split leaf philodendron", while others call the Monstera a "split leaf philodendron".
This may confuse more than clear up, but that is what we deal with when there are no pictures, only common names!