Removing Roadblocks to Rigor: Linking Academic and Social ...
Removing Roadblocks to Rigor: Linking Academic and Social
Essentially, unnatural web links are artificial links that are meant only to manipulate web page rank and also ranking greater on the search engine result.
Introduction and Background - Unnatural Causes
Removing unnatural is the only way to revoke penalty and get your ranking back. But it is very important to sort out which links are unnatural as per Google Guidelines.