Who determines who owns a domain name? International organization? Do unrecognized countries also get their own top-level domain? If someone or some organization wanted to register a website for highly illegal activities (terrorism, crime organizations, etc) who has the authority to shut them down? Does one government has the authority, or does it require a majority of the countries? What if, say, North Korea hosted a website advocating terrorism? Who can take that down?
https://www.nslookup.io/learning/
This is a great resource to learn about how the DNS works.