Exchange Server 2016 Client Access Licenses (CALs) provide companies with the licensing rights to access the comprehensive email, calendar and communication features of Exchange Server 2016. These CALs are available in two variants and enable flexible licensing of user and device access to manage the IT environment efficiently and according to needs:

User CAL: This license allows a specific user to access the Exchange Server from different devices. It is ideal for employees who work from multiple devices or need to access server services remotely.

Device CAL: This license is designed for a single device and allows multiple users to access the system. It is especially suitable for shared devices, such as in shift work or at public workstations.