Where do we draw the line between "language" and "dialect"?

Click here for the video of Scots:
   • The Scots Language  

Things from this video I didn't make:
Picture:
http://en.wikipedia.org/wiki/Africa#m...
Intro Song:
   • Kadenza - Flight of the Breezies  
Fakoutro Song:
   • Archie - Your Life (Original Mix)  
Outro Song:
   • Silver Note - Chasing Marks