Licensing Guide
Client Licensing
CAL — Client Access License
Every user or device accessing Windows Server needs a Client Access License (CAL). This is separate from the server license — the server license grants the right to run the server, while the CAL grants the right to access it.

CAL Types
User CAL
Assigned to a specific user. That user can access the server from any device — PC, phone, tablet, from home or office.
Best for:
- Employees with 2+ devices
- BYOD (Bring Your Own Device) environments
- Remote work scenarios
- Mobile workforce
Device CAL
Assigned to a specific device. Any user can access the server from that device — ideal for shift workers sharing equipment.
Best for:
- Shift work (multiple users on one device)
- Kiosks and public terminals
- Shared workstations
- Computer labs
User CAL vs Device CAL Comparison
| Feature | User CAL | Device CAL |
|---|---|---|
| Assigned to | A user | A device |
| Access from | Any device | Only this device |
| Reassignment | To another user (90-day min.) | To another device (90-day min.) |
| BYOD scenario | Ideal | Inefficient |
| Shift work | Inefficient | Ideal |
RDS CAL — Remote Desktop Services
If users access Remote Desktop Services (RemoteApp, full desktop via RDP, VDI), an additional RDS CAL is required on top of the Windows Server CAL. This is a separate license that stacks on top of the base CAL.
Full RDS Licensing GuideRelated Articles
| Windows Server | Windows Server Core Licensing |
| RDS | RDS — Remote Desktop Services Licensing |
| SQL Server | SQL Server Licensing |