As you may already know, the Action Center in Windows 10 is now able to show and store notifications from Desktop Windows apps, system notifications, and Modern apps. The Action Center stores these notifications grouped by app and time. When a new event happens, it shows a toast notification for a few seconds and then it is stored in Action Center. Windows 10 allows you to specify which notifications show first in Action Center. It prioritizes notifications so apps with high priority notifications have their notification shown at the top of the notification center.