I know that pingback and trackback are link notification. If blog A links to blog B, blog A sends: a pingback to B, that received it and send a pingback to A to verify that it comes from there; a trackback to B, to advise the blogger B that A linked to him. B can approve this trackback, like a comment. What's the difference? A pingback is automatic, a trackback must need the blogger work. A pingback doesn't send content, a trackback do. Now, to better understand this kind of notification: a pingback is only a communication between blog platforms; a trackback, instead, is a communication between bloggers. Is it right my reasoning?