Google changes its search algorithm between 500-600 times per year, with most changes being minor. Occasionally it rolls out major algorithm updates known as Panda, Penguin, and Hummingbird. Panda updates significantly impact the algorithm and are estimated to affect 3-5% of queries. Penguin updates have been part of Google's algorithm for many years and the latest refresh impacted less than 1% of US/English queries. Hummingbird, which rolled out about a month before the provided text, pays more attention to individual words in queries as its name references being precise and fast.