What does oat bran mean in cooking?

oat bran means: These are the outermost layers of the Oat Kernel that have a high level of soluble fiber. They can be used in baking to add flavor and texture. (in Cooking Dictionary)

What else does oat bran mean?

• Oat bran is the outer shell of the oat. It’s often used to provide a high-fiber nutritional supplement. Oat bran, which is thought to lower cholesterol, is rich in vitamin B-1. Also contains good amounts of vitamins E and B-2. (in Cooking Dictionary)