Editor’s Note: This is a section of our completely redone SEO Guide. Enjoy!
Google has multiple named parts of the algorithm that influence search rankings.
Google Panda is part of the algo that is specific to the quality of content.
Google Penguin is specific to the quality of links.
Hummingbird is Google’s part of the algo for handling conversational search queries accurately.
Google Panda takes the quality of a site’s content into account when ranking sites in the search results.
For sites that have lower quality content, they would likely find themselves negatively impacted by Panda.
As a result, this causes higher quality content to surface higher in the search results, meaning higher quality content is often rewarded with higher rankings, while low-quality content drops.
When Panda originally launched, many saw it as a way for Google to target content farms specifically, which were becoming a major problem in the search results with their extremely low-quality content that tended to rank due to sheer volume.
These sites were publishing a fantastic amount of low-quality content quickly on topics with little knowledge or research, and it was obvious to a searcher who landed on one of those pages.
Google has now evolved Panda to be part of the core algorithm.
Previously, we had a known Panda update date, making it easier to identify when a site was hit or had recovered from Panda.
Now it is part of a slow rolling update, lasting months per cycle. As a result, it is hard to know whether a site is negatively impacted by Panda or not, other than doing a content audit and identifying factors that sites hit by Panda tend to have.
To learn all about Panda, please see our revised and expanded article: A Complete Guide to the Google Panda Update.
The second major Google algorithm is Penguin.
Penguin deals solely with link quality and nothing else.
Sites that have purchased links or have acquired low-quality links through places such as low-quality directories, blog spam, or link badges and infographics could find their sites no longer ranking for search terms.
Most sites do not need to worry about Penguin unless they have done some sketchy link building in the past or have hired an SEO who might have engaged in those tactics.
Even if the site owner was not aware of what an SEO was doing, the owner is still ultimately responsible for those links.
That is why site owners should always research an SEO consultant or SEO agency before hiring.
If you have done link building in the past while tactics were accepted, but which are now against Google’s webmaster guidelines, you could be impacted by Penguin.
For example, guest blogging was fine years ago, but is not a great way to build links now unless you choose your sites well.
Likewise, asking site visitors or members to post badges that linked to your site was also fine previously, but will now definitely result in Penguin or a link manual action.
To learn all about Penguin, please see our revised and expanded article: A Complete Guide to the Google Penguin Algorithm Update.
Google Hummingbird is part of the main Google search algorithm and was the biggest change to their algorithm since 2001.
What is different about Hummingbird is that this one is not specifically a spam targeting algorithm, but instead an algorithm to ensure they are serving the best results for specific queries.
Hummingbird is more about being able to understand search queries better, particularly with the rise of conversational search.
It is believed that Hummingbird is positively impacting the types of sites that are providing high-quality content that reads well to the searcher and is providing answers to the question the searcher is asking, whether it is implied or not.
Hummingbird also impacts long-tailed search queries, similarly to how RankBrain is also helping those types of queries.
Google wants to ensure that they can provide high-quality results for the longer queries.
For example, instead of sending a specific question related to a company to the company’s homepage, Google will try to serve an internal page on the site about that specific topic or issue instead.
Hummingbird cannot be optimized for, outside of optimizing for the rise of conversational search.
Longer search queries, such as what we see with voice search, and the types of queries that searchers tend to do on mobile are often highlighted with a conversational search.
Optimizing for conversational search is easier than it sounds.
Make sure your content is highly readable and can answer those longer tail queries as well as shorter tail ones.
Like RankBrain, Hummingbird had been released for a period before it was announced, and most people in the SEO industry did not notice anything different regarding the rankings.
It is not known how often Hummingbird is updated or changed by Google.
To learn all about Hummingbird, please see our revised and expanded article: How the Google Hummingbird Update Changed Search.