Same I think. I always buy oats to make porridge. Sometimes you can buy coarser/finer versions, but the they are the same. You can buy oat flour too, I use that for bread making.
Rolled oats are oat groats that have been dehusked and steamed before being rolled into flat flakes. They are sold as porriage oats except when they are, they usually have less tough bran in them. So very slightly different but still steamed and flattened oats.
Can porriage oats and flat oats be eaten "raw" or as they come? I've seen smoothie recepie that says put oats in it, but i'm not sure if to put them in straight from the box or to some how cook them first.
In the summer I soak oats ( uncooked) in soya milk with chopped apples etc. and cinnamon, leave overnight in the fridge and that makes a lovely breakfast. I can't eat hot porridge in the summer.