Your Google Algorithm Cheat Sheet: Panda, Penguin, and Hummingbird

If you're reading the Moz blog, then you probably have a decent understanding of Google and its algorithm changes. However, there is probably a good percentage of the Moz audience that is still confused about the effects that Panda, Penguin, and Hummingbird can have on your site. I did write a post last year about the main  differences between Penguin and a Manual Unnautral Links Penalty, and if you haven't read that, it'll give you a good primer.





The point of this article is to explain very simply what each of these algorithms are meant to do. It is hopefully a good reference that you can point your clients to if you want to explain an algorithm change and not overwhelm them with technical details about 301s, canonicals, crawl errors, and other confusing SEO terminologies.

What is an algorithm change?

First of all, let's start by discussing the Google algorithm. It's immensely complicated and continues to get more complicated as Google tries its best to provide searchers with the information that they need. When search engines were first created, early search marketers were able to easily find ways to make the search engine think that their client's site was the one that should rank well. In some cases it was as simple as putting in some code on the website called a meta keywords tag. The meta keywords tag would tell search engines what the page was about.

As Google evolved, its engineers, who were primarily focused on making the search engine results as relevant to users as possible, continued to work on ways to stop people from cheating, and looked at other ways to show the most relevant pages at the top of their searches. The algorithm now looks at hundreds of different factors. There are some that we know are significant such as having a good descriptive title (between the <title></title> tags in the code.) And there are many that are the subject of speculation such as  whether or not Google +1's contribute to a site's rankings.

In the past, the Google algorithm would change very infrequently. If your site was sitting at #1 for a certain keyword, it was guaranteed to stay there until the next update which might not happen for weeks or months. Then, they would push out another update and things would change. They would stay that way until the next update happened. If you're interested in reading about how Google used to push updates out of its index, you may find this  Webmaster World forum thread from 2002 interesting. (Many thanks to Paul Macnamara  for explaining to me how algo changes used to work on Google in the past and pointing me to the Webmaster World thread.)

This all changed with launch of "Caffeine" in 2010. Since Caffeine launched, the search engine results have been changing several times a day rather than every few weeks. Google makes over 600 changes to its algorithm in a year, and the vast majority of these are not announced. But, when Google makes a really big change, they give it a name, usually make an announcement, and everyone in the SEO world goes crazy trying to figure out how to understand the changes and use them to their advantage.

Three of the biggest changes that have happened in the last few years are the Panda algorithm, the Penguin algorithm and Hummingbird.

Read more about this topic : http://moz.com/blog/google-algorithm-cheat-sheet-panda-penguin-hummingbird