Network guide
What is DNS?
Reviewed 10 September 2026 · 5-minute read
DNS is the distributed naming system that maps domain names to data such as IP addresses and mail servers. Recursive resolvers follow or cache referrals to answer client queries.
From a name to an answer
- Your application asks a recursive resolver.
- The resolver uses cached data or follows the DNS hierarchy.
- An authoritative server returns the relevant record set.
- The answer may be cached for its time to live.
Common records
A maps to IPv4, AAAA to IPv6, CNAME aliases a name, MX identifies mail exchangers, NS delegates a zone, and TXT publishes text used by many verification and email-policy systems.
Why answers differ
Cached records expire at different times, operators may intentionally answer by location, and configuration changes take time to reach all resolvers. Use the DNS lookup tool for a current server-side result.