Ooooh, I love oatmeal.
"Steel-cut oats" (also sometimes called Scottish or Irish oatmeal) is the whole oat groat cut into smaller pieces. (I don't know why it is called "steel-cut.")
Regular oatmeal is an oat groat cut, steamed and flattened for faster cooking.
Instant oatmeal is an oat groat cut, more steamed and more flattened for even faster cooking.
You are getting the whole grain when you cook with steel-cut oats. In my opinion, you are also getting a much lovelier and tastier breakfast! The oats have more "bite" and taste nuttier...but they are much less creamy.
Here's my morning oatmeal ritual - take steel-cut oats, add flaxseed, cinnamon, pumpkin seed and raisins. Cook in my wee rice cooker until done. Eat topped with blackstrap molasses (for the iron), applesauce and yogourt.
Heaven! Everyone in my little family eats this breakfast nearly every day.