Oats pl. : of Oat

Example:
Help! Can someone tell me the difference between rollled Oats and oat bran?

Taxonomy
Oats, groats, oat groats, bushel, cereals, grain, rolled oats, soluble fiber, oat bran, oat flour, yields, acre, protein, wheat, barley, oatmeal, flour, whole oats.

Defination from the web:
Oats in SK near harvest time ... Domesticated oats appear relatively late, and far from the Near East, in Bronze Age Europe. ... Oats are grown throughout the temperate zones. ...