Licensing RDS

Remote Desktop Services (RDS) is a Microsoft technology that enables users to access and use applications or desktops remotely (previously known as Terminal Services). 

RDS CALs are required for each user or device that directly or indirectly accesses the Remote Desktop Services functionality.

There are two types of RDS CALs: 

• User CAL: This license is assigned to a specific user and allows that user to access RDS from any device.
  With this model, each user who accesses RDS functionality requires a User CAL. This model is suitable when multiple devices are used by a single user to access RDS.

• Device CAL: This license is assigned to a specific device and allows any user to access RDS from that device.

With this model, each device that directly or indirectly accesses RDS functionality requires a Device CAL. This model is suitable when multiple users share a single device to access RDS.

Note: No RDS CALs are required for up to two users to access instances of the server software for administration purposes

RDS CALs are required to access Virtual Desktop Infrastructure (VDI) only required if any of the following technologies are in use;
Remote Desktop (RD) Gateway, RD Web Access, RD Connection Broker, RD Session Host, or RD Virtualization Host. 

Please note, that Remote Desktop Licensing Server ID is required to generate proper license.

Customers should review the official licensing documentation and consult with a Microsoft licensing specialist to ensure compliance and determine the most suitable licensing approach for their specific requirements.

Additional materials from Microsoft:

Licensing Windows Server Remote Desktop Services