How to use Notification Summary in iOS 15

Apple's new iOS 15 introduced a new Notification Summary and all it does is give you one snapshot of what's been going on — but it's so handy.
Craig Federighi introduces Notification SummaryCraig Federighi introduces Notification Summary
Sometimes the simplest ideas are the best. Rather than the ping, ping, ping of notifications all day, you can shut them out, or at least cut them down, with Focus Mode. And then catch up later.