TrackBack is a type of peer-to-peer communication system that was designed to send notification of updates between two Web sites via a Trackback Ping. Ping in reference to TrackBack refers to a small message sent from one Web server to another. TrackBacks are useful for informing a Web site that you have referenced its Web site within your own Web site, and is popular with bloggers.
TrackBack was first released as an open specification in August 2002.
