This was a more technologically advanced version of the Penguin algorithm that changed the way the algorithm influenced search results.
Penguin 2.0 impacted approximately 2.3% of English queries and proportionally impacted queries in other languages.
This is also the first update to Penguin, which searches deeper thailand whatsapp number than the site's homepage and top-level category pages for evidence of link spam pointing to your site.
Google Penguin 2.1: October 4, 2013
The only update to Penguin 2.0 (2.1) occurred on October 4 of that year. It affected about 1% of queries.
Although Google has not made an official explanation for this, the data shows that the 2.1 data refresh also increased the depth of Penguin's viewing and crawling of websites, and conducted further analysis on whether they contained spam links.
Google Penguin 3.0: October 17, 2014
While this was billed as a major update, it was really just another data refresh; allowing those users impacted by the previous update to emerge and recover, while many others who continued to use spammy link practices and escaped previous impact were impacted.
Google employee Pierre Far confirmed this via a post on his Google+ profile, saying the update will take "a few weeks" to roll out fully.
Far also said that the update affected less than 1% of English search queries.
Google Penguin 4.0: September 23, 2016
Nearly two years after the 3.0 update, the final update of the Penguin algorithm was released.
The biggest change in this iteration is that Penguin has become part of the core algorithm.
When an algorithm transcends to become part of the core, it does not mean that the functionality of the algorithm has changed or is likely to change dramatically again.
This means that Google’s thinking about the algorithm has changed, not that the algorithm itself has changed.
Now, Penguin runs concurrently with Core, evaluating sites and links in real time. This means you can see the impact of your link building or remediation efforts (reasonably) instantly.
The new Penguin algorithm is no longer stingy when it comes to penalizing links, but rather reduces the value of the links themselves. This is in stark contrast to the previous Penguin algorithm, which penalized negative links.
That being said, from research and personal experience, algorithmic penalties related to backlinks still exist.
Soon after the Penguin algorithm was introduced, webmasters and brands that used manipulative link building techniques or stuffed their backlink profiles with a large number of low-quality links began to see a decline in their organic traffic and rankings.
Not all Penguin demotions are site-wide, some are partial demotions that only affect certain heavily spammed and over-optimized keyword groups, such as key products and in some cases even brands.
It took 17 months for a site that was penalized by Penguin to have the penalty lifted.
Penguin’s effects can also be transferred between domains, so changing domains and redirecting the old domain to the new one may cause more problems in the long run.
Experiments and studies have shown that using 301 or 302 redirects will not eliminate the effects of Penguin, and in the Google Webmaster Forum, John Mueller confirmed that using meta refreshes from one domain to a new domain could also cause complications.