The shape of the edge
Technically, anytime you change the angle at which the edge of a blade is ground, you are re-profiling it. However, for normal sharpening, that is just part of the process sometimes, and I don't charge any extra for it.
My Re-profiling service is essentially a repair. If you have a micro-serrated blade, it will stay "sharp" for a long time, but once it is dull it can't be resharpened unless those tiny "teeth" are ground smooth and the edge is re-profiled. If you have a knife like this, click here to schedule re-profiling service. Many other types of serrated edge knives (bread knives, Cutco knives, etc., can be resharpened without grinding the serrations off.
For any service requiring the use of a grinding wheel, I always use a paper wheel with grinding compound (either silicon dioxide or diamond) on the surface. This provides a gentle, cool grinding process that removes the necessary steel without overheating the blade. Using a stone grinding wheel can easily ruin a blade in just a second. Don't let anyone use a stone grinding wheel on your knives!