TED stands for Technology, Entertainment, Design. It started out (in 1984) as a conference bringing together people from those three worlds. Since then its scope has become ever broader.
The annual conference now brings together the world's most fascinating thinkers and doers, who are challenged to give the talk of their lives (in 18 minutes).
Try this really great example of a TED Talk by clicking below:
Hans Rosling: Debunking third-world myths with the best stats you've ever seen