In early 2011 the Google Panda also known as Farmer was released. This update affected many websites and was designed to improve the quality of the websites in the search index. Google Panda tackled low quality content of websites and this algorithm changed the Search Engine Optimisation world forever.
Why Panda name? Google employs an engineer named Navneet Panda. Before Panda, machine learning scalability at Google was at level X, and after it was at the much higher level Y. So that was quite nice. Thanks to Navneet, right now they can scale up this machine learning.
Why does Google created Panda? Panda updates are suppose to focus on penalising the ranking of sites with a poor user experience and improves the ranking of sites with a positive user experience.
It keeps in mind you - person who uses Google to search forr information. You want to find a website that provides an answer to what you are looking for, not a website with a bunch advertisements. After all, if you could not find what you were looking for on Google you would no longer use Google.
I would like to point out here that Panda use automatically applied filters that adjust the rankings of all websites based on the content and marketing method employed. A website that has been affected by Panda can be recovered. Recovery may not be an easy task!
Panda is something new and different for SEO. For a long time every SEO has been doing the same - 1. been building good content, 2. making it accessible to search engines, 3. doing good keyword research, 4. putting those keywords in there, 5. and then trying to get some links to it. Till Panda we never really had to think about users experiences. Thanks to Panda to become good in SEO we have to use strategy and design Internet experiences!
Penguin: Penguin is designed to penalise those who buy links from ‘link farms’ or ‘link exchanges’ back to their website. However, fact is that in Penguin, Google isn’t taking action on “low-quality or spammy sites”. Google is taking action against sites being LINKED TO by “low-quality or spammy sites”. If your website rankings dropped in Google, or even disappeared over night chances are – then you have been caught up in Google’s latest update to combat unnatural links - Penguin!