Quiet Hours is a feature in Windows 10 that disables showing all notifications. Any notifications you get while Quiet Hours is turned on will still appear in the Action Center for you to review later.
Are there certain times when you don’t want to be interrupted or just need to stay focused on what you’re doing? Starting with Windows 10 build 17074, you can automatically choose those times when you don’t want to be bothered with Quiet Hours automatic rules.
The priority list allows you to manage which notifications are allowed. The rest will go straight to action center when you have Quiet Hours turned on to Priority only. Alarms will still work though.
This tutorial will show you how to customize your priority list for Quiet Hours for your account in Windows 10.