Robin came across this delightful resource for grains, a Grain Glossary. In part, it says, “Most people know brown rice when they see it, but what about all the other grains? It’s one thing to rattle them off, but it’s an entirely different matter to know their various nutritional profiles and how to cook them. Then there’s the confusion of defining or classifying grains, as some grains that we call grains are not. True grains belong to the cereal grass family; for this glossary, however, I include edible seeds that share the nutritional properties of whole grains (quinoa, buckwheat, wild rice).
The bulk bins can be bewildering; even when you’re familiar with a particular grain, it’s mind-boggling to make sense of all the names it may go by. Groats, grits, steel-cut, rolled, puffed, pearled, cracked, flakes, and flour are the most common references, and all describe how the grain has been processed.” [Culinate (dot) com]
They have listed some of the more popular, and somewhat confusing grain types, in a good chart that also shows you what the grain looks like, much like the photo above from their website. For instance, for polenta they state that, “Polenta
Polenta and grits may sound as disparate as Italy and the South, but they’re both ground corn, as is cornmeal. They differ in how they’re ground (both the method and the fineness of the grind). Avoid de-germinated cornmeal (the germ has been removed to increase its shelf life), as it’s not a whole grain. Polenta makes a delicious base for sauces (ragu, mushroom, gorgonzola) and sausages; it’s also good grilled or layered into lasagne-like dishes.”

There is more listed in the article. A good read! Enjoy the information. Cheers!