To enable visitors to share the page on Google's social network
Not all of the Google news of late focus on Google Drive, Google+ remains a very important project at Google. It's always getting new features or improvements, the most recent being a share button for websites which enables visitors to, well, share the page on Google+.The share button joins the existing +1 button in enabling websites to integrate Google+ functionality and hopefully spur engagement. The Google+ Share button works as you'd expect, click on it and you get the very familiar Google+ sharebox, the same one Google uses for all of its properties not to mention in the navbar.
"When your visitors come across something interesting on your site, sometimes you want to encourage a simple endorsement (like +1). Other times, however, you want to help visitors share with their friends, right away. Today’s new Google+ Share button lets you do just that," Google explained.