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 is 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 avoid these 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 automatic or manual adjustment to the search results.
There's a continuum at play in the world of black hat....