Every year Google tweaks and adjusts their search algorithm. Most of these modifications are minor, however, over the last 365 days the search engine mega-giant had made 6 MAJOR updates. If you're the counting sort, go back a few more years and you'll see the combined total is a jaw-dropping 39 major updates. Well, get ready because it's probably going to happen again next month in May.
Why May? For the past 2 years Google has released two big updates in May which focused on mobile websites; as such, the Internet is currently abuzz with the new hashtag – #mobilemay. With the evolution and expansion of the Internet and web technology, it's not unreasonable for Google to refine and update their search algorithm. However, if you've been paying any attention to the big Google updates lately you know mobile-friendly websites are reaping the rewards when it comes to page rank and those who aren't mobile friendly are falling further and further behind.
To learn more about what Google's expected to change and what you should do about it, here's a great introductory article on it: read the article.