Licensing works by how many active URL sessions are running.
When you setup a display or agile instance a URL link is created.
You can manage the playlist for the display/agile instance and choose the pages that are displayed on them.
Display is full screen high resolution so mostly used for TVs but can be used on any screen.
Agile is for smaller resolutions i.e desktop PCs, tablets, mobile phones
Agile can be used for agents/managers to have on their laptop or PC, mobile phone or tablet whilst working on other things.
If you have created 6 URLs and they are all actively streaming through a browser then each will use a license (if you have created 6 URLs but they are not being actively used in a browser it shouldn't effect the license), if you are actively using 1 URL 6 times that would use 6 licenses. Or any combination.