This term generally refers to massive blocks of text within or across several domains that are carbon copies of other content or are very close to matching it. There are two forms of duplicate content – malicious and non-malicious. The latter would include printer-only versions of articles on a website as well as discussion forums. The former occurs when content is purposely duplicated across multiple domains with the sole intention of manipulating search engine rankings and gaining more traffic. This practice is abhorred by the search engines (especially because it provides a poor user experience) and websites containing duplicate content are usually booted out of the index.