[sonvi.belani]

Hi,
Google introduced the Disavow tool to help webmasters remove links that might be considered spam, and are therefore targeted by its Penguin algorithm. (The Penguin algorithm punishes domains that use black hat SEO practices or have backlinks from disreputable sources, so they drop to the bottom of search engine results pages.)

The Disavow tool is not meant to help publishers maintain their link profiles – it’s meant to be a last resort for webmasters who have already done the heavy lifting to repair their sites according to Google’s SEO best practices. The search engine introduced the tool to help people who had already made initial attempts to get rid of spam and low-quality links, but were unable to remove them all and were still being punished in SERPs.

To use the Disavow tool, publishers can submit a text file (in .txt format) containing the links and domains they want Google to ignore when crawling their profiles.
Thanks