BuddyPress helps you run any kind of social network on your WordPress, with member profiles, activity streams, user groups, messaging, and more.
A family of standard web feed formats used to publish frequently updated information like blog entries, news headlines, audio and video.
A pingback is one of four types of linkback methods for Web authors to request notification when somebody links to one of their documents. This enables authors to keep track of who is linking to, or referring to their articles.
Open graph description entity tag
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".