The face of the sharpening stone is generally considered to be the widest surface on either side of the stone. This is the area of the stone upon which you sharpen your tools.
Edge
The edges of the sharpening stone are typically narrower. This area of the stone is not usually used for sharpening (especially on stones with a coarse side and a fine side).
Fine side
Many sharpening stones are double-sided and include a fine-grit side and a coarse-grit side. The fine side is typically used in the later stages of the sharpening process.
Coarse side
The coarser side of the sharpening stone is used in the early stages of the sharpening process.
