Unprocessed (unroasted) groats are white. They can be used as is for sprouting, or as a substitute in dishes calling for rice. Some people find their flavour mild; others recommend toasting them in oil for several minutes to remove a flavour they find slightly bitter.
Roasted groats are brown and are cracked into coarse, medium or fine granules. They have a slightly nuttier flavour than white owing to being roasted. When sold, they will usually be called “kasha”, a word from Eastern Europe, where this grain has been popular for centuries as a side dish and as an ingredient in many main dishes. These cannot be used for sprouting.