Authoritative DNS refers to the official name servers that publish the source-of-truth records for a domain zone. When a resolver asks where a domain points, authoritative servers provide the final answer for records such as A, MX, and TXT. They are different from recursive resolvers, which only look up and cache answers on behalf of clients.
In cyber security, authoritative DNS matters because it sits on a trust path for web traffic, email delivery, and domain validation. If an attacker can change authoritative records, they may redirect traffic, intercept services, or satisfy certificate issuance checks used by TLS providers. Defenders treat these servers and their control panels as critical infrastructure: restrict administrative access, use strong change control, monitor for unexpected record edits, and alert on certificate transparency activity that may indicate fraudulent validation. Even brief unauthorized changes can have outsized impact.