In CMS each administrator can have different access to different plugins and sections in the administration panel. This can be handy if you have an admin only manage the news, so he/she doesn't need access to your blog or settings.
Admin access are separated in three levels.
This has to be done via the db.php file, any administrator must be in the db.php file, more information can be found in following FAQ Article - Add more Super Administrators.
This option can be found if you are an Super Administrator from your site under General Settings - Plugins/Hooks *.
General Access will give your admins access to following:
Human Verification, Settings, Site Setup, Search Log, Login Log, User and User-group.
Manage Access will give your admin access to following:
Categories, Pages, Contact Form
Each plugin has his own access level, if you like to give access to any of your plugins to your administrator's, simple add the userid into the input field, if you have more then one separate them by comma * (e.g. 3,5,65,75).