A sharp knife is much safer and easier to use than a dull one. Before every use of your kitchen knife, it should be honed (aka steeled), which is the process of realigning micro-sized bends along the knife’s edge from its last use. Honing quickly reforms and straightens the knife’s cutting edge to restore its sharpness. However, honing should not be confused with sharpening the blade. Sharpening is done with a whetstone, ceramic rods, sharpening gadgets, or an electric sharpening machine. Sharpening actually removes metal from the edge to create a new edge.
Even with routine honing, a knife blade will need sharpening from time to time. Sharpening removes metal from the blade to create a new edge. A whetstone (or sharpening stone) is the most traditional tool for sharpening. There are many, many kinds of sharpening stones, but all will have an abrasive surface of some degree (grit). The coarser the surface, the more metal the stone will remove from the blade; the finer the surface, the less metal it will remove. Your sharpening stone should be as long as the longest blade you sharpen. As in honing, you will want to achieve the correct edge angle for which a mechanical edge guide is useful.
A manual pull-through knife sharpener eliminates the need for a mechanical edge guide. The sharpening slot is pre-set to ensure the correct angle every time.
Electric sharpening machines are available from the very inexpensive to the expensive, but as it often is, you get what you pay for, and an inexpensive electric knife sharpener may actually damage the edge of expensive cutlery. Better electric knife sharpeners will have multiple slots with from coarse to fine bevels to achieve a super-sharp blade edge.
In closing, don’t neglect honing your knife every time you remove it from the block, and from time to time, sharpen the edge. And if you have expensive, high-performance cutlery in your kitchen, match it with high-quality tools for keeping it sharp.