Basically, Hummingbird is an added algorithm with the ability to answer questions, predict user intent, and keep users on Google search longer…thus improving search experience and ultimately, revenue from google ads. But read the article to get a full picture.
Read more at http://www.searchenginejournal.com/google-hummingbird-means-online-marketers-seo/71577/#2ODyRt0ApuIoXVVy.99