Hi @Morne Marnewick ,
Yes it is used for Users logging into the RDP servers that might be hosting any applications, if users are using Windows 8/10 computer are they connecting via VPN and accessing apps,SQL etc? So Remote Desktop CALS are used to assign a license to each user connectining and accessing a RDP server.
When a user or a device connects to an RD Session Host server, the RD Session Host server determines if an RDS CAL is needed. The RD Session Host server then requests an RDS CAL from the Remote Desktop license server. If an appropriate RDS CAL is available from a license server, the RDS CAL is issued to the client, and the client is able to connect to the RD Session Host server and from there to the desktop or apps they're trying to use.
Hope this helps.
==
Please "Accept the answer" if the information helped you. This will help us and others in the community as well.