Porridge is a dish made by boiling ground, crushed, or chopped cereal in water, milk, or both, with optional flavourings, usually served hot in a bowl or dish. It may be sweetened with sugar or served as a savoury dish. The term is usually used for oat porridge; there are similar dishes made with other grains or legumes, but they often have other unique names, such as polenta, grits or kasha.
A dish made of oats alone, either in crushed or meal form, or whole-grain, is known simply as oatmeal in the U.S. and parts of Canada. Hot cereals are often prepared as instant breakfasts.