There are 3 different types of administrators for yappa-ng:
This is the guy who has shell-access and/or ftp-access to the webserver and who is responsible for the complete yappa-ng installation.
He can change the central config.inc.php - file, where all yappa-ng - global options are defined (=run the setup.php script).
These global settings are eg the paths of yappa-ng, if image-caching is used, which languages are used or if different templates are availlable - and much more.
In most cases this yappa-ng admin will be YOU !!! ;-)
And in most cases you will create an album (and if you don't use it for your own purpose) give the admin-password for THIS NEW album to an Album-Admin.
This can literaly be everyone who gets an adminpassword to an album.
In most cases this will be a friend, a family member, a collegue, a member of your club - or could even be a paying client.
The Album-Admin can configure 'HIS' album to his liking, can upload/delete/rotate images, can change the thumbnail-layout and the image-sort-criteria, can decide if he wants to use image-hits-counters, Top-10-reports, can write/edit/delete image captions and album-descriptions in all languages, can set userpasswords and much more.
He can also create new sub-albums WITHIN 'HIS' album and give it another admin-password!
But outside of 'HIS' album/subalbums he is just another user who can only view other albums (if he got a userpassword from the other album-admin). ;-)
If the yappa-ng Administrator permitted (enabled) the "Upload only Admin" in the global configuration than the Album Admin can give a second Admin-Password to each Album.
If you log in as Album Admin with this second password your actiona within this Album-Admin Menu are really restricted. The only actions which are permitted are:
This "Upload-only-Admin" setting is for all album-admins who want other users to load their images into the Album but do not want them to be able to edit the album info, delete the album or change the album layout!