Every notification you receive is highlighted by a numeric counter on the bell icon on the top right corner of your screen. Simply click on the bell icon to view the received notifications. Notifications may vary by user within an account, based on the permission levels of sub-account users.
Once you open the notification list, notifications are considered read, and the numeric counter is reset. Each read notification stays in the list until the X to its right is clicked and it is dismissed. The notification list only contains the 50 most recent un-dismissed notifications.
To view past notifications, click on View Previous Notifications at the bottom of the notification list, or navigate to Notification Center within Settings. The Notification Center contains all notifications received in the last six months. All prior notifications are automatically archived.