Link Farm

[Michael]

A group of sites which are linked to each other site to artificially get increase in Page Rank is known as 'Link Farm'.
This was an effective technique sometimes ago but now Search Engines consider it as Spam technique.

 

[James]

Link Farm is the web page where number of links placed over this page to get backlinks and traffic but yes you are right that now this page count in Spam Technique

 

[min]

On the World Wide Web, a link farm is any group of web sites that all hyperlink to every other site in the group.[1] In graph theoretic terms, a link farm is a clique. Although some link farms can be created by hand, most are created through automated programs and services. A link farm is a form of spamming the index of a web search engine (sometimes called spamdexing). Other link exchange systems are designed to allow individual websites to selectively exchange links with other relevant websites and are not considered a form of spamdexing.