Users (staff with access to the Agent Interface) who want to test a booking should use an alias email for testing and not their 'real' email.
ie: Use email@example.com & not firstname.lastname@example.org
Using your 'real' email will cause your login to break because Groupdesk will think you are a traveler who should not have login abilities on the Agent Interface.
Permissions control the access your roles have on the Agent Interface. The 'Eye' enabled means they are able to view the details of this category. The 'Pen' enabled means they are able to edit everything to do with this record type or area. If you change the view/edit ability on this page, it affects all users who hold that role.
Most of our clients prefer to give 'view' access to all users but limit the editing access.
Roles determine the level of permission for your users.