What is linkfarm?

[market]

I have encountered the phrase - 'Link Farm'. I am aware of links, back links, hyperlinks, etc. And now I read linkfarm - what is it?

[Ronald Marva]

A link farm is collection of websites which contain hyperlinks to increase significantly page ranking of targeted sites in search engines. Although some link farms can be created by hand, most are created through automated programs and services.

This is considered a black hat trick as some companies have been shut out by Googles from their search results because of this.

Link farms were developed by SEOs circa 1999 to take advantage of the search engine's dependence upon link popularity.