Google+ platform websites integration using the Google+ platform tag.
BuddyPress helps you run any kind of social network on your WordPress, with member profiles, activity streams, user groups, messaging, and more.
See what your Facebook friends have liked, shared, or commented on across the Web. This includes all variations of Like, Share and Follow Buttons, Embedded Posts, Comments, Activity Feed, Recommendations Feed, Recommendations Bar, Like Box and Facepile.
Let visitors recommend your content on Google Search and share it on Google+.
Open graph description entity tag
Open graph title entity tag
Sites who has this tag are verfied by google to use WebMaster tools
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".