Reprofiling means changing the angle or the grind of the blade. Most come with about a 20 degree angle on each side, = 40 degree inclusive. I find that 25 degrees is the ticket for me on my outdoor blades. A wider angle will be more durable & generally last longer, 25 & 30 degree are wide angle. A thinner angle, say 10-15 degree, will seem sharper but will have the possibility of chipping or denting or rolling over easier. Kitchen knives have thinner angles than outdoor knives---usually. Sometimes a new knife will arrive with a blade edge that is off center, then the low side has to be reprofiled so that the edges meet in the center---not off to one side or the other. Thats about the best i can describe it. Someone else may be able to help by posting pics.