Hello
Thank you for posting in Q&A forum.
Yes, if you use Windows Server to manage users or devices, you typically need to purchase the appropriate Client Access License (CAL) for each user or device.
Microsoft Server's licensing model usually consists of two parts:
Server License: This is the license for the server itself running Windows Server software, such as purchasing a core license for Windows Server.
Client Access License (CAL): This is the right granted to a user or device to access the server and its services (such as file services, print services, Active Directory services including GPOs, etc.). Depending on your needs, you can choose between user CALs (licensed per user, no limit on the number of devices used) or device CALs (licensed per device, no limit on the number of users using the device).
User CALs (Client Access Licenses) are indeed designed for users accessing server services. Server services covered by user CAL include but are not limited to: file and print services, Active Directory services, Remote Desktop Services (RDS), etc.
When using RDS, in addition to server licenses, you typically require RDS CALs, either user CALs or device CALs, depending on your licensing model.
In fact, the act of joining the domain itself does not directly require a CAL. In other words, when a device joins a domain or a user account is created in the domain, it does not immediately trigger the need for CAL. The need for CAL is when these users or devices start to actually access CAL-protected server services, such as obtaining resources through domain authentication, applying GPO, or accessing shared files.
For more information, please refer to the following links:
Client Access Licenses (CAL) & Management Licenses | Microsoft Volume Licensing
License your RDS deployment with client access licenses (CALs) | Microsoft Learn
I hope the information above is helpful.
Best Regards,
Yanhong Liu
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