This update was released in all countries and languages simultaneously; nonetheless it was an ongoing update that took a week to fully roll out. The update also received a lot of media attention because it’s one of only a few updates that was announced well in advance of its release by Google, who also suggested website owners to prepare for it.
The update causes mobile-friendly websites to appear more frequently in search results. That is to say – making a website compatible with mobile devices becomes a parameter in determining a website's ranking. The official announcement states that only mobile searches will be affected, and in reality it would seem that after the update the results have fluctuated even less than expected.
Another change caused by this update: users that are logged in to their Google account will see content from apps that are installed on their mobile devices in their search results. This subject is very significant and greatly impacts mobile device search result visibility.
Points regarding this update:
Official information from Google:
Google's official announcement on the update can be found here: https://googlewebmastercentral.blogspot.co.il/2015/04/rolling-out-mobile-friendly-update.html
A team from Google answered questions regarding the update for an hour this week. The full segment can be found here: https://www.youtube.com/watch?v=v-0Q4s9ThU0
How to deal with this update?