Google Penguin is a change in the search engine algorithm of Google that was first announced on April 24, 2012. Under this update Google reduces the rankings of websites that are found to be indulging in unethical or ‘Black-Hat SEO’ practices. This decrease in ranking of a website by Google is commonly referred to as the Google Penalty and recovery from this penalty is commonly known as Penguin Recovery.

Black Hat SEO practices include use of artificial means to increase the rank of a web page by manipulating the number of links that are pointing to that page. This artificial manipulation occurs when webmasters indulge in wrong practices such as participating in link building schemes or getting associated with link farms. The latest version of Penguin that has been released by Google in October 2013 is Penguin 5 with Penguin 2.1 spam-filtering algorithm

Why is the Google Penguin update relevant?
The Google Penguin update becomes relevant because it was found that there were several websites that had started to buy links in order to boost their rankings. Rather looking at the quality of the link or the reputation of the site, importance was being given to the number of links that were pointing to a website, no matter whether these links came from reputed websites or whether they came from websites that were of a low rank or came from the category of ‘spammy’ websites. Google felt that this was a negative industry trend that had to be reversed and that is why they introduced the update.

How does the Google Penguin update affect SEO? 
Google has established a set of quality guidelines known as Google Webmaster guidelines that need to be followed by Webmasters. Violation of any of the guidelines might result in stiff action from Google including imposition of a penalty. Some of the common acts of violation include cloaking which means writing text that can be understood by machines only and not by humans or by building ‘spammy’ links. Google always encourages ‘White Hat SEO’ practices that include writing rich and relevant content, using innovative ideas to make web pages more appealing and interesting to users thereby inviting them to visit the website again, using social media platforms to link websites and attributing authorship to articles or industry news/ blogs that appear as content pages on a website. From a design perspective also, sites with a good UI and better user experience gained through good navigation are given a weightage.