Glossary · ENCheck a domain

DNS zone

A DNS zone groups together the records managed for part of the DNS naming system. It contains records for the names it serves and can assign responsibility for a subdomain to a separate zone managed by another set of name servers. A zone is the data served by authoritative DNS servers; it is not necessarily identical to a whole registered domain.

How is a zone different from a domain?

A domain is a name and its position in the DNS hierarchy. A zone is the portion of that hierarchy for which an operator publishes the official DNS data. For example, example.com can be one zone, while shop.example.com can be delegated into a separate zone. The parent zone keeps delegation information that points queries toward the child zone's name servers.

The zone's data commonly includes NS records listing authoritative name servers and one SOA record with management information. Other records, such as A, MX, and TXT, provide service-specific information. A DNS host may let an administrator edit these records through a dashboard, while the actual zone is served by authoritative servers.

What happens when a subdomain is delegated?

The parent zone contains a delegation, information that tells DNS lookup services (resolvers) which name servers can answer for the child zone. The child zone then holds its own authoritative records. A parent can still contain ordinary records for names that have not been delegated. Delegation is a boundary of DNS administration, not a transfer of the domain registration.

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