What is the difference between honing and sharpening a knife?
Sharpening removes metal to create a new cutting edge. Honing removes almost none — it straightens an edge that is still sharp but has bent out of alignment. They are different operations, and confusing them is why many people think their knives dull far faster than they should.
A knife edge tapers to a few microns across. That thin margin of steel is easily deformed sideways by contact with a board, a bone or a hard crust. Once bent over, it no longer presents a cutting edge to the food, and the knife feels blunt even though no metal has been lost. The steel rod that comes with most knife blocks pushes that fold back into line. That is honing, and it takes seconds.
Because honing costs almost nothing in metal, it can be done frequently — many cooks hone briefly before each use, and a rod every few uses is plenty for a home kitchen. It will restore a knife that has gone slightly dull almost instantly.
Sharpening is a different matter. When the edge has genuinely worn away, chipped, or been rolled so often that the fatigued steel breaks off, honing stops working. Now you need to grind new steel away on a whetstone, a pull-through sharpener or a powered system until a fresh edge is formed. This shortens the life of the blade slightly each time, so it is done occasionally — a few times a year for typical home use.
The practical test: if honing restores the edge, the knife needed honing. If it does not, it needs sharpening.
Ceramic knives cannot be honed at all — the material does not deform, it chips — and need proper sharpening or replacement.