The term black hat SEO, generally refers to any manner, by which visibility, rankings, or traffic is improved through illicit or forbidden techniques, tools, or methods. There are a wide variety of techniques that fall under black hat: Spamming forums, spamming blog comment areas, automated link exchange schemes, browser hijacking, cloaking, link farms, keyword stuffing, article spinning, paid links, and many more. The goal of this chapter is to help you sort the good from the bad, and avoid the worst techniques and the websites that employ them.

The search engines push back against the black hat methods; they've gotten better and better at detecting and punishing illicit techniques. Generally, when black hat methods are discovered, Google and other search engines will impose either a penalty or a filter (we'll learn about the distinction between those two concepts) by making an automatic or a manual adjustment to the search results.

There's a continuum...