SQL Server 2016 Licence
May be the following links may help you:


https://www.microsoft.com/en-us/sql-server/sql-server-2017-pricing
https://www.brentozar.com/archive/2015/04/microsoft-sql-server-licensing-simplified-into-7-rules/
https://www.brentozar.com/archive/2014/09/first-concern-sql-virtualization-licensing/