Google Updates
1. Panda
February 24/2011
Important Points: Duplicate Content Check, Copy or thin content, keyword stuffing
2. Penguin
April 24/2012
Important Points: Spammy or irrelevant links, links with over-optimized anchor text
3. Hummingbird
August 22/2013
Important Points: Keyword stuffing, low-quality content
4. Pigeon
July 24/2014 (US), December 22/2014 (UK, Canada, Australia)
Important Points: Poor on- and off-page SEO
5. Mobile
April 21/2015
Important Points: Lack of mobile version of the page, poor mobile usability
6. RankBrain
October 26/2015
Helping Hand of Hummingbird
Important Points: Lack of query-specific relevance, shallow content; poor UX
7. Possum
September 1/2016
Important Points: local results, competition in your target location
8. Fred
March 8, 2017
Important Points: targets websites Thin, affiliate-heavy or ad-centered content