As far as I know, oat is a cereal. In America, "boxed cereals" conjures up images of Captain Crunch or Frosted Flakes, which are full of sugar, and usually eat

As far as I know, oat is a cereal. In America, "boxed cereals" conjures up images of Captain Crunch or Frosted Flakes, which are full of sugar, and usually eaten cold with cold milk. Oatmeal, while it may be a cereal and may come in a box, is usually not placed in the same group as it is usually eaten hot.