An Open Fan Differs from Turboprop and How It Beats Turbofans [video]

Normally I hate the video links posted here, but I did this one with subtitles and 2x speed and it was informative, and the diagrams for once aided comprehension.

It made some things which have confused me in the ontology of fan/prob/turbo/jet clearer, and it explained a lot about why we've wound up with fully ducted fans, powered by jet engines with a high bypass ratio.