What is a client licence?
Client licenses (or CAL – Client Access License) give users legal access to Microsoft server software for Windows, SQL server, and Exchange server. The license by itself does not grant the individual or device the right to connect the server. Each client license must be obtained by each user.
Server manufacturers that distribute software with servers can provide client access licenses. The CALs purchased together with the server give the same rights as those purchased separately. Many people don’t know that Microsoft no more delivers client access licenses for Windows Server licensed through OEM channels.
Types of client licenses
There are two types of client licenses. Depending on how many devices employees use or whether different people work for the same device, you can optimize your costs by choosing the right type.
User CALs
You can purchase CALs for each employee depending on how many users you have. It doesn’t matter how many devices the workers use, the CALs can be purchased for all of them. If your employees need access to the corporate network via multiple devices, or if it is not clear from you which devices they will access, it makes sense to purchase the CALs based on the number of users. They can also be useful in situations where there are more users than devices.
Device CALs
You can purchase licenses for each device that connects to the server, depending on how many you have. It doesn’t matter how many people use a licensed device. Device CALs can be used to reduce administration costs and simplify administration for companies that have multiple employees.
Multiple servers can be found in large organizations. It is helpful to know that a CAL can be assigned to a user or device so that they can legally work with them.
Are CALs necessary if users/devices don’t connect directly to the Microsoft server software
A company might use a particular server product for accounting, personnel management, etc. It may also have its own licensing system. This product can access Microsoft’s server software such as SQL Server. Multiplexing is used to describe this system. To use the scheme legally, you need a license (in this case SQL Server CAL). It must be able to access the Microsoft server software.

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