The short: Panda’s purpose was to favor high-quality sites with great content while punishing low-quality sites with thin content. The long: The Panda update was released into the wild on February 23, 2011 and affected a ton of sites (reportedly almost 12% of all search results). At first, SEOs thought the algorithm hit sites with unnatural backlinks, but eventually, everyone realized that links probably weren’t a part of the Panda update. Instead, it was focused on on-site quality and content- three types of content in particular.
The recovery: Amit Singhai of Google wrote an incredibly helpful guide on how to recover your rankings if you think you’ve been hit by the Panda update. Basically, it boils down to offering high-quality content (he lists questions to ask yourself to determine if your site is high quality) and removing low-quality content from your website. Also, for duplicate content in cases such as the e-commerce example, use the rel=canonical tag to show Google that one URL is equivalent to another URL for search purposes.
The short: Penguin focuses on punishing sites with unnatural links that try to get an unfair advantage in Google’s search results. The long: Penguin hit April 24, 2012, and its aim was to catch sites that spammed search results by buying links or getting links through link networks whose primary goal was to increase Google rankings. It used to be that quantity was more important than quality with links- but not post-Penguin. The Penguin update, a sitewide algorithm, hurts sites that have tried to manipulate links by, for example, creating self-made links and using only exact match anchor text. Now, if Google sees that you have a ton of low-quality sites linking to you, they’re think that you’re trying to cheat your way to Page One rankings, and your site will be punished accordingly. A link from another site is like an endorsement from them, and Google notices when you’re endorsed by impressive sites. The recovery: Take it back. That is, identify the bad links to your site and remove them, if possible, by asking the webmaster of that site to remove them. Or, if you can’t do that, disavow the links using the disavow tool. Once Penguin refreshes again, you’ll be back in Google’s good graces, assuming you’ve eradicated your most offensive unnatural links.
The short: Hummingbird takes your whole search into account, instead of just searching for each word individually. The long: Hummingbird is smart, y’all. Debuting in August of 2013, the Hummingbird update was a brand new search algorithm that Google created, although it still used parts of the old Panda and Penguin updates. Instead of looking at each word in particular and then searching for it, Hummingbird looks at the query as a whole, so that your search (and your results) are contextual. Hummingbird tries to understand the “why” behind a search, not just what the search is. It’s Google’s attempt at making your search conversational, and it’s called Hummingbird because it’s “precise and fast.” Let’s look at an example. Say you’re hungry on a business trip in Chicago and you have a craving for the best Chicago hot dog you can find, so you type into Google.com, “where’s the best place for a chicago hot dog.” Google recognizes that by “place,” you mean a physical location that’s probably a restaurant, and that by “best,” you’re searching for highly rated restaurants. So with that in mind, here’s what Google comes up with:
Since they change so often and so quickly, Google algorithm updates are tough to keep up with, but these are the major updates that you need to know to succeed in SEO. You can also combat ignorance and stay informed with tools such as Moz’s Google Algorithm Change History timeline (which also includes major Google updates such as the death of Authorship) or Alltop with a search specific to recent Google news. In the end, it comes down to this: Searchers want answers. Google wants searchers to get answers. Therefore, your goals should be to create content that will answer searchers’ questions in the most helpful, informative, and authoritative manner possible. Keep your users at the front of your mind, and strong Google rankings (and no penalties after updates) should follow.