An SQL license refers to a type of software license specifically for SQL Server, which is a relational database management system developed by Microsoft. SQL stands for Structured Query Language, which is used to manage and manipulate databases. There are different types of SQL Server licenses, and the cost can vary based on the number of cores in the server, the number of users or devices that will be connecting to it, or other factors such as the edition of SQL Server (e.g., Enterprise, Standard, Web, Express). When purchasing an SQL license, organizations have the option to either license the server and then purchase additional client access licenses (CALs) for each device or user that will be connecting to the server, or they can opt for a 'per core' SQL license. A 'per core' license covers the server and allows for an unlimited number of devices or users to connect to that server, which can be more cost-effective for organizations with a large number of users. read more >>

As outlined above there are two distinct ways to license the CAL side of things. You can license the server and then each device or user connecting to it OR purchase a 'per core' SQL license. The 'per core' option licenses the server and allows an unlimited amount of devices or users to connect to it.read more >>