You should realize that rolled oats and oats come from the same cereal grain. The main difference between the two is how they are processed. Oats can come in three forms they can be steel-cut, rolled, or instant. This time, oats come from oat groats then they will be processed so that they can become one of the three types that are available. Usually, steel-cut will come from oat groats that will be chopped.
This can result in a longer cooking time. Rolled oats are flat and uneven discs that can hold their shape even when they are cooked. This is faster to cook as compared to steel-cut oats. Instant oats are the most processed type of oats. This would just require hot water before it can be mixed and consumed.