Flour can be made out of a variety of grains. Oats, wheat, rye, barley, etc. There are different types of four made with wheat. White flour, all-purpose flour, bread flour, cake flour and whole wheat are all types of wheat flour. The difference in the types of wheat flour are basically the type of wheat and the grind of the flour. Bread flour is a flour that gives a nicer "rise" to breads.