SQL Server 2017 Device CAL (Sql Svr2017 Std SNGL OLP NL DvcCAL)
Licensing software with CALs and MLs can be complicated due to the technical nature of server products and networks. Microsoft offers a device-based CAL (Device CAL) or a user-based CAL (User CAL) for purchase. In addition, an External Connector (EC) license is offered for some products as an optional alternative to address specific customer scenarios.
For managing devices, Microsoft offers Server MLs for managing server operating system environments (OSEs). For managing non-server devices, Microsoft offers OSE Client MLs and User Client MLs.
This overview is for reference purposes only. Before purchasing, you should visit the "How to Buy" section for each product and consult your Microsoft representative or local reseller regarding your specific licensing needs.
With a Device CAL, you purchase a CAL for every device that accesses your server, regardless of the number of users who use that device to access the server. Device CALs may make more economic and administrative sense if your company has workers who share devices, for example, on different work shifts.