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.