I recently bought a new book entitled "The Ultimate Sourcebook for Knitting and Crochet Stitches" by Reader's Digest. While looking through, I noticed that in the "edges" section, it talks about binding on. I thought maybe they meant binding off, but the patterns say things like bind on 2 then bind off 2. What does this mean? Is it the same thing as casting on? Thank you for any help you can give me.