What is DNS?

The Domain Name System, which maps names like example.com to IP addresses and other records.

DNS is a distributed database of records (A, AAAA, MX, TXT, NS, CNAME and more). Resolvers cache answers for the record's TTL, so changes take time to reach everyone.

Comparing two independent resolvers, as our DNS lookup does, shows when caches disagree during a change.

Try it

• DNS lookup tool

Related terms

• WHOIS: The original plain-text protocol (port 43) for looking up who registered a domain.
• A record: A DNS record that points a hostname to an IPv4 address.
• AAAA record: A DNS record that points a hostname to an IPv6 address.