Google updates its algorithms multiple times on an annual basis in response to user feedback, new research and discoveries, and new technologies. These updates also serve to tackle new ways of attempting to game the system to get a higher ranking in SERPs than a website might otherwise deserve, as these methods surface. Two of the major changes Google did in the past several years were the introduction of the Panda and Penguin algorithms, designed explicitly to crack down on black-hat SEO and cut down on the visibility of websites that were improperly influencing SERPs with low-quality results which weren’t really relevant to users.