A link farm is a collection of interconnected websites created solely for the purpose of generating backlinks to other websites. Essentially, a link farm is a form of link scheme that supports unethical link building practices.
Link farms frequently resemble ordinary websites, except their content quality is often poor and they exhibit an overtly high link density. Sometimes link farms are manually created, but they are often constructed using automated software, which can make these websites appear even more suspicious to search engines.
The overarching goal of a link farm is to assist website owners in manipulating (and improving) their search engine rankings. These site owners typically pay the link farm for this illicit service.
Utilizing a link farm goes directly against SEO best practices and constitutes a violation of Google’s Webmaster Guidelines. While this unethical link scheme might temporarily improve a website’s rankings, Google’s web crawlers are becoming increasingly sophisticated.
Therefore, it is highly likely that link farms will be detected, and any associated sites will face punishment in the form of decreased rankings or even manual actions.