Method of sharpening knives with steel
A steel is used to realign the edge, allowing it to slice cleanly. Sharpening a blade removes metal to produce a new edge on a dull blade. The process of realigning the edge is also called 'honing'. My electric shapener has three slots to perform various levels of sharpening. One of them is just to hone the knife. The steel rod with a handle that comes with most knife sets serves the same purpose.