Google Penguin
It is a good question,
mariabrean! I think this Wikipedia's article will answer it:
Google Penguin is a code name for a Google algorithm update that was first announced on April 24, 2012. The update is aimed at decreasing search engine rankings of websites that violate Google’s Webmaster Guidelines by using black-hat SEO techniques, such as keyword stuffing, cloaking, participating in link schemes, deliberate creation of duplicate content, and others.
Naming the algorithm updatePenguin update went live on April 24, 2012. However, Google had not come up with an official name for it until two days later.
Penguin’s effect on Google search resultsBy Google’s estimates, Penguin affects approximately 3.1% of search queries in English, about 3% of queries in languages like German, Chinese, and Arabic, and an even bigger percentage of them in "highly-spammed" languages. On May 25th, 2012, Google unveiled the latest Penguin update, called Penguin 1.1. This update, according to Matt Cutts, was supposed to impact less than one-tenth of a percent of English searches.
The differences between Penguin and previous updatesBefore Penguin, Google released a series of algorithm updates called Panda[8] with the first appearing in February 2011. Panda aimed at downranking websites that provided poor user experience. To identify such websites, a machine-learning algorithm by Navneet Panda was used, hence the name. The algorithm follows the logic by which Google’s human quality raters determine a website’s quality. In January 2012, so-called page layout algorithm update was released, which targeted websites with little content above the fold. The strategic goal that Panda, Penguin, and page layout update share is to display higher quality websites at the top of Google’s search results. However, sites that were downranked as the result of these updates have different sets of characteristics. The main target of Google Penguin is spamdexing (including link bombing).
Google’s Penguin feedback formTwo days after Penguin update was released Google prepared a feedback form, designed for two categories of users: those who want to report web spam that still ranks highly after the search algorithm change, and those who think that their site got unfairly hit by the update. Google also has a reconsideration form through Google Webmaster Tools for the 700,000 sites who received an email stating their sites demonstrated unusual linking.
http://en.wikipedia.org/wiki/Google_Penguin#The_differences_between_Penguin_and_previous_updateshttp://en.wikipedia.org/wiki/Wikipedia:Text_of_Creative_Commons_Attribution-ShareAlike_3.0_Unported_Licensehttp://wikimediafoundation.org/wiki/Terms_of_use I hope it will answer your question and you will be a good white hat or/and green hat SEO master