Good look at what’s changed with Notifications by Juli Clover, MacRumors.

What struck me most about this redesign is the notification tuning made possible in the Notification Summary interface:

For Notification Summary, you can select specific times for notifications to be delivered, and decide which app notifications will be relegated to the Notification Summary. You can choose just a handful of apps or all of your apps.

This is definitely worth experimenting with if you feel a bit overwhelmed with notifications, need to rein them in a bit.