A server CAL (Client Access License) is a required license that gives the right to access services from Microsoft server software. Every user or device that accesses or uses the server software requires the purchase of a Windows Server CAL.
A User CAL is a license for every named user to access a server (from any device) regardless of the number of devices they use.
User CALs are ideal for companies with employees who need to have roaming access to the corporate network using multiple devices, as well as from unknown devices.
Window Server 2012 CALs
- If the workstations in your organization are networked, you likely depend on network server software to perform certain functions, such as file and print sharing. To legally access this server software, a Client Access License, or CAL, may be required. A CAL is not a software product; rather, it is a license that gives a user the right to access the services of the server.
Note: You must have a Windows Server 2012 CAL to access an instance of Windows Server 2012