If a knife feels dull, that may be for one of two reasons: it could be that the edge isn’t as sharp as it was previously, or it could be that the blade is out of alignment. Both of these will cause the knife to feel blunt and mean it doesn’t cut as efficiently. While you might be used to seeing someone wielding a steel—or honing rod—to “sharpen” the knife, what they’re actually doing is realigning the blade, gently pushing it back to a central position so it cuts better. To sharpen, or re-edge a knife, you need to grind or shave metal from the edge of the blade to make it pointier—rather like sharpening a pencil. This tool both realigns and sharpens, so your whole knife block will be eligible for an upgrade.