What is HDR, WCG and Dolby Vision and why does it matter?

Alphabet soup starring HDR and WCG  “Hey Guys, let’s re-invent the entire TV and Cinema chains from Camera to Screen!” said no high-ranking executive in any board meeting ever. The whole concept sounds like crazy talk when you say it out loud, but in reality that’s what the High Dynamic Range (HDR) and Wide Color Gamut (WCG) revolution have done over the…