from the book "Art of SEO":
301s carry cross-domain functionality, meaning you can redirect a page at Domain1.com to Domain2.com and carry over those search engine metrics. This is not the case with the canonical URL tag, which operates exclusively on a single root domain (it will carry over across subfolders and subdomains).
What does the 1st line mean? Say if I move domains, I can 301 the old domain to the new and have the same search engine ranking?
I don't really get how the canonical tag fits into the picture. Can someone explain?