Online marketers know that SEO is constantly evolving in response to major changes to the search engine algorithms. Google has made strides to improve its organic search results by releasing the Penguin, Panda, Hummingbird, and other algorithms. These algorithms have reduced the number of spammy, irrelevant, and low-quality results in the organic portion of the SERPs.
Panda—which was released in February 2011 and has since undergone numerous iterations—works to reduce the rankings of low-quality sites that provide “thin” content. Meanwhile, Hummingbird—which was released around August 2013—can be described as a major breakthrough in conversational search. According to the article, “Four SEO tactics to Embrace in 2015”, which was published on the Hubspot blog, “With Hummingbird, Google proved that they now understand what your page is about; they know the topic of the page, how unique the content is, and how well it’s written.”
http://seomarketingmachine.com/white-label-seo-services-four-seo-tactics-to-implement-this-2015/
SEO Marketing Machine 