Apple's Focus: What does it do and how does it work?

Apple introduced Focus at this year's WWDC. This is likely to be a quite useful tool for any iPhone, iPad, or Mac user attempting to get things done, or trying to put some space between work and personal life.What is Focus?
Focus is a nuanced version of Apple’s existing Do Not Disturb tool. It combines the ability to block out unwanted interruptions with contextual awareness and granular controls in a way that Apple hopes will help users remain focused on the tasks at hand.To read th