Method of sharpening knives with steel The following is an extract from 'How to Cook Everything' by 'Mark Bittman' about sharpening knives:


  An electric sharpener is the best, easiest, and most
  expensive way to keep knife blades sharp; even moderately
  serious cooks should consider this a worthwhile
  investment. The alternatives are to learn to use a whetstone
  (not that difficult, and very effective, but timeconsuming)
  or to take them to a hardware store to have
  them sharpened professionally.
  A steel is a handy tool for maintaining the edge of
  knives between sharpenings. (You should use it every few
  days, at least.) It’s nothing more than a sturdy rod stuck
  in a handle, but it takes some practice to get the hang of
  it


Firstly, this addresses how we could sharpen knives - an electric sharpener or whetstone do the same job of sharpening. Then it mentions that a (sharpening) steel helps in maintaining the edge of the knives between sharpenings.

Does this mean that, in order to sharpen knives, we need an electric sharpener/whetsone and a sharpening steel? Can we just use a sharpening steel to sharpen knives - why?

Sorry if this seems like a silly question. I've not been taught anything about sharpening knives, and only know of its practice. My understanding is that we can sharpen knives using either a sharpening steel, or a whetstone. I've never heard anything about 'maintaining the edge of knives between sharpenings' as Mr Bittman states in his book
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.