You do need to have both. But 1 of each is enough.
Access privileges are associated with Sections, as are Forums selection for discussions.
Icons are associated with Categories.
See my site for more detailed descriptions.
Note the Default Section and Default Category are not used for display, they are/were there as catch-alls in case of errors on set up, but also serve as set up areas for Admins - who can see them - to create new articles without their WIP being seen.
Okay, I understand sections and categories. Thanks for that. I should probably go to your website with more questions. I did try out all the templates, and they don't seem to show the image at the left and the text at right - but I suppose I need to play some more...
Server specs (Server OS / Apache / MySQL / PHP / DragonflyCMS):
Linux/PHP Version 5.2.17 MySQL Version 5.5.32-log (client: 5.5.32)/Dragonfly 126.96.36.199