Group admins are allowed to manage their group.  This can be useful in scenarios where you want leads to manage their groups and assign their users to events, and email their group.  As a admin of your Duplie instance, you can also invite Group Admins to events.  This will send the admin a single email which will automatically log them in to assign their users to the event.  The token will automatically expire once the event passes.  Using this method, you are not actually inviting the individual users, you are requesting the group admin to communicate with their group members and sign them up on their behalf.  The users who are signed up will still receive the reminder notifications.  Group admins will also receive a reminder to sign up their group as the event gets closer (if there are openings available).

To invite a group admin, you will go into an event and Invite.  On the modal you should see Group admins.  On that screen you can filter the groups to a specific admin.  These group admins must have been added as admins of the group and given access to manage event roles for their group.