In order to minimize cooking time, other types of oats are processed to a greater extent. For instance, a steel tool is used to cut steel-cut oats into extremely small pieces. As the grains turn smaller, it becomes very easy to make oatmeal.

Rolled oats are created using another type of processing. Firstly, they are steamed, following which they are leveled through squashing. These oats are then dried up, after which they can be stored in your kitchen over a long period. This level of processing ensures that the cooking time is reduced.  

Scottish and instant oats are two other types of oats. In the case of Scottish, oats are basically made into a meal, while the latter is developed by subjecting the groats through steaming and leveling process. Moreover, they are also slightly cooked to enable you to enjoy oatmeal without any hassles.  

Although these aspects are all quite interesting, it is important to not determine the oats that you must consume merely on the basis of the processing involved. At the end of the day, regardless of the variant you choose, you would still be consuming whole grains. The nutritional aspects of every type of oats are quite similar.