Whole-wheat flour (in the US) or wholemeal flour (in the UK) is a powdery substance, a basic food ingredient, derived by grinding or mashing the whole grain of wheat, also known as the wheatberry.
Whole-wheat flour is used in baking of breads and other baked goods, and also typically mixed with other lighter “white” unbleached or bleached flours (that have been treated with flour bleaching agent(s)) to restore nutrients to the white flours (especially fiber, protein, and vitamins), texture, and body that are lost in milling and other processing to the finished baked goods or other food(s).

Source: Wikipedia