you coulda just googled sir: http://en.wikipedia.org/wiki/Google_Panda Google Panda is a change to the Google's search results ranking algorithm that was first released in February 2011.[ Code (markup):
Google panda is mainly focusing on quality content. So it is very important to have quality content in order to sustain in the market and enhance your website presence.
Google Panda is a change to the Google's search results ranking algorithm that was first released in February 2011.The change aimed to lower the rank of "low-quality sites", and return higher-quality sites near the top of the search results.
Google has launched back to back panda updates to prevent search engine results from content farmers and give better search results to their valued customers.