Many terms in this document are specific to the DNS. This glossary contains short explanations of these terms. For more information, RFC 7719 (DNS Terminology) can be consulted.


The query type used to request a full zone transfer. Commonly used to refer to the act of transferring a zone.


A Fully Qualified Domain Name is a domain name that specifies its exact location in the DNS hierarchy.

primary server

A “primary” zone (or server) acts as a source of truth for a zone. secondary servers will check at the primary server if their zones are still up to date.


A “native” zone does not used DNS-based data replication but for instance database replication.

NS record

NS records in a zone declare the name of the nameservers authoritative for that zone.

record set

A record set is the collection of DNS records with the same name, type and TTL.


The organization that allows registration of names in the zone. These organization operate the TLDs. For .nl this is SIDN and for .com this Verisign

secondary zone

A “secondary” zone (or server) retrieves its zone data from a primary server.

SOA record

Only one “Start Of Authority” record exists in a zone. It indicates that this domain is indeed a zone.

Top Level Doman

A Top-Level Domain is a a zone that is one layer below the root, such as .nl and .com.

Zone file

The de-facto storage format for DNS zones. This format is text-based and lists all records in a zone, one per line.