Flattening and cleaning stones
A flattening stone is typically used to level or flatten the surface of a sharpening stone. As a sharpening stone is used repeatedly, it tends to wear more in the middle of the stone than along the edges. If the sharpening stone is not kept flat your knives and tools will develop slightly rounded edges and become much less effective at cutting. To keep your stone flat you periodically lap it on the surface of the flattening stone.
