How does DNS work?
The Domain Name System associates names such as example.com with information. Your device asks a recursive resolver, which uses cached answers or queries authoritative nameservers. When necessary, it follows referrals through root and top-level-domain servers. Browsers and operating systems can also cache answers.
Important record types
A and AAAA provide IPv4 and IPv6 addresses. MX specifies mail servers and priorities. CNAME is an alias, TXT carries information such as SPF or DKIM, NS identifies nameservers, SOA describes the zone, and PTR provides reverse-DNS names. SRV describes services with ports, priorities and weights; CAA controls which certificate authorities may issue certificates.
TTL and changes
TTL limits how long a cached answer may be used. Updates therefore do not appear everywhere immediately. Missing records, NXDOMAIN and failed queries are different outcomes. Without MX, an A or AAAA record can act as an implicit mail destination in certain circumstances; missing MX does not prove universal mail failure.
Privacy and measurement location
Traditional DNS uses UDP or TCP and is normally unencrypted. DoH and DoT encrypt the connection to the resolver, which still processes the query. DNSSEC checks authenticity but does not encrypt. Our DNS lookup runs on the server; its results do not automatically identify the resolver used by your browser or VPN.