Glossary · DNS
Top-level domain
The last label of a domain name, such as com, org or fr: a zone one level below the DNS root, run by a registry.
What it means
Top-level domains divide into country-code TLDs (fr, uk, de) and generic TLDs (com, org, and newer ones such as shop or email). IANA keeps the list in the root zone database. From DNS's point of view there is nothing special about them; the differences are policy.
The registrable domain is not always one label below the TLD: in example.co.uk the public suffix is co.uk, which is why DMARC needs the organizational domain concept.
Related terms
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- RFC 9499: DNS Terminology, section 2rfc-editor.org
- IANA: Root zone databaseiana.org
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