Rewrite term explained
Rewrite is called the process of re-writing of the text, when changing the form of the text, but the essence remains unchanged. Useful of rewriting in SEO that readers don't see the change text, and search bots can see taking rewriting for unique content.
Also rewriting is used to avoid copyright infringement, in this case the test original is presented in your own words.
Rewriting is used not only for text but also for any of the content (media content, HTML, headers). When optimizing a website firstly need rewriting of the pages for that they correspond to certain keywords, and only after this start website promotion with the help of external factors.