What license is required for the server domain controller?

Question

Windows Server

In connection with the growth in the number of users in the organization (now 20 people, plans for 5 more), they began to think about moving from a workgroup to a domain.
What type of server license is needed in this case? Do I understand correctly that server standard 2019 is enough? Or it is necessary for each user then to buy them in addition?

Answer 1

Standard license based on the number of cores and CAL by the number of users or workstations.