Google announced on late Friday afternoon plans to use a website's mobile version as the primary content source for ranking sites for its search engine's results, in a move that its engineers have hinted at for the past year at several SEO conferences.
A few years back, in order to encourage webmasters to support mobile versions of their websites, Google started adding a "Mobile Friendly" tag next to certain search results and later started ranking these sites above desktop-only content.
Today, most websites are already mobile friendly, and earlier this year, Google removed the "Mobile Friendly" tag from search results, saying that over 85% of the sites it indexes include a mobile version, making the tag redundant.
Because webmasters chose to support mobile sites via various techniques, there are a few things that webmasters need to know, according to Google.