Starting April 21, 2015, Google announced in this post that users on mobile devices should get more mobile friendly web pages served to them. What does that mean? More mobile friendly web pages will display in your search results when searching Google on your smartphone.
Is your site Mobile-Friendly?
See their link to Mobile-Friendly Test here
This means that your site may not show prominently during a search if it doesn’t display well on a smartphone or tablet. Having a mobile friendly website is now more important than ever if you want your site to appear in the search results. See our post on Responsive Website Design to read more.