What is the quantum/classical divide?

A talk given at the University of Buenos Aires in June 2017 on the difference between classical systems and quantum ones: https://www.youtube.com/watch?v=kvXYmB2qj88&feature=youtu.be   (Note: Some of the slides were missing text here and there due to a compatibility issue; the correct version is provided here:¬†Baires 2017 slides)