Google penguin
 

Any one can help me, what is Google penguin? How it works.

1) Penguin Helps the Natural way Of back linking
2) Don't use Link Schemes
3) avoid duplicate Content

Penguin update is the latest Google update affecting sites with a severe lack of natural links. They say it�s the same update (with some improvements) that Google first released by the name �Over-optimization update� and then the Webspam update.

Here is a detailed post on what it is, how it works and how to escape being hit by this update:
http://www.keywordcountry.com/blog/g...urvival-guide/