Yes, they are the same. Yellow mustard is the classic American squeeze bottle mustard you get in the grocery next to the ketchup. It's also called prepared mustard because there is a process of grinding mustard seeds and mixing them with other ingredients to make the sauce. Yellow mustard seeds are the mildest of all mustard seeds which makes this variety of mustard the mildest of prepared mustards. If mustard is prepared with brown or black mustard seeds the product will be spicier with more heat.