DNS has a vocabulary that documentation tends to assume. This is the short version.
The things you manage
| Term | What it means |
|---|---|
| Zone | Everything KumoDNS answers for one domain. One zone per domain you host here. |
| Record | One answer inside a zone — a name, a type and a value. |
| Apex | The bare domain, example.com, as opposed to www.example.com. Also called the root or naked domain. |
| Subdomain | Any name below the apex. www, mail, api. |
| Label | One dot-separated part of a name. www.example.com has three. |
| TTL | How many seconds a resolver may cache an answer. See SOA and TTL. |
| FQDN | Fully qualified domain name — the whole name, ending at the root. |
The things that answer
| Term | What it means |
|---|---|
| Nameserver | A server that answers DNS queries. |
| Authoritative | Holds the zone and answers from it. Ours are authoritative for your domains. |
| Resolver | What your computer asks. It walks out to the authoritative servers and caches the answer. Also called recursive. |
| Root | The top of the tree. Knows which servers run each TLD. |
| TLD | Top-level domain — .com, .sg, .org. |
| Delegation | The parent zone naming which nameservers are authoritative for a child. This is what your registrar changes. |
The things that go wrong
| Term | What it means |
|---|---|
| NXDOMAIN | The name does not exist. |
| SERVFAIL | The resolver got an answer and refused it — often DNSSEC failing. |
| REFUSED | The server you asked is not authoritative for that zone. |
| Propagation | A word worth unlearning. Nothing propagates; caches expire. See publishing. |
The ones people mix up
Registrar and DNS host are different jobs. The registrar is who you bought the domain from and renew it with. The DNS host answers lookups for it. Moving your DNS here changes only the second, and one setting at the registrar. See what KumoDNS is.
A domain and a zone are not quite the same. The domain is the name you registered; the zone is the set of records answering for it. One domain, one zone, in almost every case.
Primary and secondary describe the zone, not the quality. A secondary zone transfers its contents from a primary elsewhere. See zone types.
Related
Last reviewed 2026-09-16.
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