Mills or millstones in ancient times

The millstone is a stone used in a mill to grind grain, and it works manually, or by the force of animals, or by the force of wind or water current. Including the circular stone mill, which is two stones that form a circle and separate from the middle, and the first is placed on the second in a parallel manner, and the material to be grinded is lowered from a small hole in the middle of them, and it is moved by hand until the material is ground, and it is a machine that is still used in some Moroccan regions.