Good video for getting a feel of what XML is about.
Jean Paoli - Co-creator of XML, part I
Jean Paoli - Co-creator of XML, part II
It's cool to see someone like Jean Paoli, who really knows a lot and can explain things in simple terms (maybe because he knows a lot).
It's amazing how complicated explanations can sometimes get as you move from original sources. On the other hand often if you talk to the originator, or someone close to the origination of some thing (a design, a book, a program...most any thing) they can give you an explanation to fit your needs.
People who understand concepts, "why", and history are invaluable. Of course we need detail oriented people to work out the implementation, the "how". But someone has to be able to tell the story.
Jean Paoli does a nice job in the video.