I've always wondered what all this rdf stuff is about. People who know about tend to rave about it. I recently watched a video presentation from Tim Berners-Lee (the guy who invented the net) about linked data, as was still unsure what he was talking about by the time he finished. http://www.ted.com/index.php/talks/tim_berners_lee_on_the_next_web.html

I then watched a video about rdf in Drupal, which explains via example the power of rdf. I can now see the power of rdf. I won't try to explain it. Check the video.