Preferences is the setting in which you can adjust Themes, Languages, and Notifications.
Notifications Tab
Administrators (including Permission Admins, jira-administrators, and site-admins) will be able to access notification enablers, in which All Users will able to enable/disable email notifications. Notification Admins will also be able/unable to switch the app notification button in this tab.
Action
In this section, Administrators can give permission to all users to enable/disable Email Notification Enabler. All users (including Notification Admins) therefore will be allowed to turn on/turn off the email notifications at their disposal.
Admin Notification
Admin Notification switchers mean for Notification Admins. Switch the buttons to enable/disable App Notification (and Email Notification if allowed).