In some ways, the Google algorithm is like the deep sea giant squid of the SEO marketing field. We all know it's out there, somewhere, but knowing specifically what the algorithm is doing is often shrouded in mystery. Like researchers looking for evidence in washed up debris, search engine optimization engineers are often looking at how traffic is routed to websites in order to figure out what the latest changes to the algorithm have been.

While Google doesn't completely publicize the entirety of its algorithm, it does, fortunately, make the public aware of major implemented changes. Over the years, changes to the Google algorithm have helped shape the course of the web itself, as certain websites were shuttled out of search results forever, while others were promoted.

Anyone working with or using SEO should know the basics about the algorithm changes and how they have affected the SEO tactics currently in use today. Here are some of the big and more recent updates you should be aware of.

July 2014: Pigeon

The latest "bird" to enter Google's melee, Pigeon has altered how the Google algorithm handles local search results. For this reason, Pigeon has had a noticeable impact on SEO dealing with small businesses, which are typically local in nature. In some cases, businesses received a boost: local directories have been prioritized. In other situations, though, individual websites for hotels and restaurants, etc., have been pushed back behind more categorical websites.

April 2012: Google Penguin

Throughout the past several years, Google has made consistent efforts to thwart black-hat SEO techniques (illegitimate search engine-manipulating techniques), and Penguin was no exception. This update helped to further push out manipulative practices such as link schemes, keyword stuffing, and other types of excessive spammers.

February 2011: Google Panda

Panda was a big change to the internet, affecting about 12% of all search results. Have you ever been on a page that provided you little information, and was mostly ads? These have become less common since Panda, which was intended to address the issue of low-quality, "thin" sites, and worked to promote higher-quality sites in search results. Google used Google Quality Raters to help it categorize high and low quality sites by asking them to rate sites using questions such as, "Would I trust this site with my credit card?"

Have any of these updates impacted your page rank? Let us know in the comments.

By: Mari Rogers