Notification Center on your Mac
Notification Center keeps all of your important information, reminders, and widgets in one convenient place. Get details about calendar events, stocks, weather, and more—and catch up on notifications you might have missed (emails, messages, reminders, and more).
Open Notification Center. Click the date or time at the top right of the screen, or swipe left from the right edge of the trackpad with two fingers. Scroll down to see more.
Interact with your notifications. Reply to an email, listen to the latest podcast, or view details about calendar events. Click the arrow in the top-right corner of a notification to view options, take action, or get more information. With iPhone Mirroring, you can interact with iPhone notifications directly on your Mac.
Set your notification settings. Open System Settings, then click Notifications to select which notifications you see, including whether you would like to see iPhone notifications on your Mac. Notifications are sorted by most recent.
Pause notifications to focus on what you’re doing. When you’re working, having dinner, or just don’t want to be disturbed, Focus can automatically filter your notifications so you see only the ones you specify. Focus can pause all notifications or allow only certain ones to appear, and it can tell contacts that your notifications are silenced using a status in Messages. To set up Focus, open System Settings, then click Focus in the sidebar. To turn Focus on or off, click 
You can customize a Focus to fit what you’re currently doing, and allow notifications from certain people or apps, for phone calls or upcoming events, and more. You can also share your Focus across devices and use Focus filters to hide distracting content in apps like Calendar and Messages.
Customize your widgets. Click Edit Widgets (at the bottom of your notifications) to see the widget gallery and add, remove, or rearrange widgets. If you are signed in with the same Apple Account on your iPhone and your Mac, you can also add your iPhone widgets to your desktop without having to install the corresponding apps on your Mac. You can drag new widgets anywhere on your desktop or in Notification Center. You can also add third-party widgets from the App Store.
Learn more. See Use Notification Center on Mac.