Penguin

The Penguin filter, or Google Penguin, is an update to Google’s search engine algorithms that was first announced in April 2012. The purpose of this update was to penalize websites that were having bad quality and relevance link coming in or out of the website. 

More specifically, the Penguin update targeted the quality et relevance of links coming in and out of a website. When a new Penguin update is released, sites that have taken action to remove bad links (such as through the use of Google’s disavow links tool) may regain rankings. New sites not previously caught might get trapped by Penguin. “False positives,” or sites that were caught by mistake, may escape.