What is Permaculture?

 I was asked by a friend who was watching my last garden update, WTF is Permaculture? I tried explaining but my response seemed inadequate. In fact, I felt I was rather obtuse. Therefore, I decided to let others explain what permaculture is. 

And if this is isn't adequate one can always to go to YouTube or a regular internet search to learn more. There is plenty of information out there. So, go, and find out what permaculture is.