Each license is tied to a subdomain (Basic), domain (Advanced or Premium) and IP (Premium), and can run only on that subdomain/domain/IP. Besides the subdomain/domain/IP, the same license can run on localhost and private networks (classes A, B and C).
For example, if you buy a Basic license for intranet.domain.com you can't use it on documents.domain.com. If you buy an Advanced license, you can use it on *.domain.com, this is all subdomains of a domain, but on others domains such domain2.com or domain3.com. And a Premium license can be tied to a domain (as Advanced) or a whole IP for all domains and their subdomains that share the same IP.
If you don't know or don't have a subdomain/domain/IP, you can write localhost and change it other day if needed.