With all this talk about Penguin, Panda, and Hummingbird updates it gets very difficult to know really what is going on and why these Google search algorithms are so important. Here’s a little bit of background:
Google has about 1,500 PhDs working on its search algorithm every day. These smart people are trying to make the Google machine better at answering your questions. Whenever they make a tweak to the code, there is an algorithm update. Most of the times, these updates only effect a small percentage of websites on the Internet. Other times, however, these updates have a huge impact on a large number of websites.
One of the biggest updates to the Google search engine was rolled out in February 2011. It was called the Panda update. What made Panda so interesting was that it affected up to 12% of searches (according to Google).
Also, Panda seemed to be targeted directly at certain SEO techniques. Pre-Panda, an SEO company could rank a website by using a lot of “thin content” that would be good enough to not get caught by Google’s SPAM filter.
For example, you could get a piece of software mix together articles that would be considered complete gibberish and have those articles rank for different keywords.
Oftentimes, these websites would have tons of ads all over the place to capitalize on the free SEO traffic.
Panda continues to get updated. In July of 2015, we had Panda 4.2 “refresh”. So Google is apparently keeping its engineers hard at work.