

Every user and every device that connects to a remote desktop session host requires CAL (Client Access License) licenses. Use the Remote Desktop licensing service to install, issue, and track Remote Desktop Services CAL licenses.
When a user or device connects to a Remote Desktop Session Host server, the latter determines if a Remote Desktop Services CAL license is required. The Remote Desktop Session Host server then requests a Remote Desktop Services CAL license from the Remote Desktop Licensing server. If an appropriate Remote Desktop Services CAL license is available on a Licensing server, the license is issued to the client to allow the connection to the Remote Desktop Session Host server and from there to the desktop or apps they are trying to use.
Use the following information to learn about the functioning of Remote Desktop Services CAL licenses and to distribute and manage these licenses:
Grant CAL (Client Access License) for the distribution of Remote Desktop Services
Information on the CAL License Model for Remote Desktop Services
Compatibility of Remote Desktop Services CAL License Versions
Information on the CAL Remote Desktop Services license model
Two types of Remote Desktop Services licenses are available:
CAL licenses for Remote Desktop Services device
CAL Licenses for Remote Desktop Services User