What exactly are whole grains? And what's the difference between whole grains and fibre?

Whole grains are when the full-grain includes in the cereals.

The grain consists of four different parts called bran, sprout, endosperm and shell parts. The bran is a concentrate of the shell parts of the nucleus. The sprout is the predate for the growing plant, while the endosperm, or flour body as it also is called, contains starch and some proteins. Sifted flour such as wheat flour and rye flour only retains the endosperm from the grain. Shell parts are simply the shell and its parts around the grain.

You could only find whole grains in cereals, i.e. wheat, rye, barley, oats, rice and maize and a few other kinds of cereal. Fibre can you found in other foods, such as fruit, root vegetables, lentils and beans. In the whole grain, there is, among other things, a part that is the fibre itself. Whole grains have more benefits than just their fibre content and affect health in different ways. Whole grains are among the best nutrients for intestinal bacteria, creating a healthy intestinal flora.

Does it matter if the whole grain is whole, crushed or minced?

For health's sake, the differences are marginal. Whole grains are best for smoother blood sugar. When you crush the entire grain, the body will more easily access all the vitamins and minerals. All varieties are suitable, and the baking itself can determine what is best suited for the purpose.