olemus
kõrgeimal hierarhiatasemel domeen Interneti domeeninimede süsteemis, näiteks mingi maa domeen

Wiktionary:
(computing, Internet) the last component of a domain name, such as .com, .edu, .gov, .net, .org, .mil, .mobi or any of the newer generic top-level domains, or any of the ccTLDs

ülevaateid
https://en.wikipedia.org/wiki/Top-level_domain
https://en.wikipedia.org/wiki/Country_code_top-level_domain
https://en.wikipedia.org/wiki/List_of_Internet_top-level_domains
https://www.oecd-ilibrary.org/docserver/232630011251.pdf?expires=1641193932&id=id&accname=guest&checksum=4D4E7B06F075B455E6362204114F1CF7
https://iwantmyname.com/domains/domain-name-registration-list-of-extensions

standardid
https://datatracker.ietf.org/doc/html/rfc1591
https://datatracker.ietf.org/doc/html/rfc2606
https://datatracker.ietf.org/doc/html/rfc6761
https://www.rfc-editor.org/rfc/rfc4185