There are two different kinds of rolled oats. Thick versions have bigger, whole flakes often used to make old-fashioned oatmeal and as an ingredient in sweets like oatmeal raisin cookies and granola. Thin versions are made of smaller flakes that have been broken into smaller pieces, and they are great for making baby food and instant oatmeal. The thinner rolled oats can also be ground into a powder and used to make thick soups or stews.
Rolled oats look like flat, irregularly round, slightly bumpy discs. They are also called “old-fashioned” or “whole” oats.