Google PandaGoogle launched Panda in February 2011, mainly as a change in its search results ranking algorithm. The main purpose of the update was just to keep those low quality and low content sites away from the top ranking results and give the actual quality sites their due.
As an obvious result, many websites with huge amount of advertising, or those with low quality content, saw a huge decline in the rankings. Ever since Panda was launched, there have been many updates to it ranging to over 22 in total.
Google PenguinAnother algorithm update from Google that gave SEO experts another blow was Penguin that was launched in April 2012. The idea underlying the update was simple enough- penalize and decrease the rankings of sites that breach Google’s Webmaster Guidelines set the by the search engine.
This included lowering the search engine rankings of all those sites that practice black-hat SEO techniques like duplicate content, keyword stuffing and cloaking to name a few.