DNS Records Explained for Website Owners

Why DNS records matter

DNS is the directory layer that tells browsers, mail servers, and other clients where a domain should go. When a website is moved, email is changed, or a CDN is added, DNS records are usually part of the change. A small typo can send visitors to the wrong server or stop mail delivery.

Common record types

• A points a hostname to an IPv4 address.
• AAAA points a hostname to an IPv6 address.
• CNAME aliases one hostname to another hostname and is often used for CDNs or hosted services.
• MX tells mail servers where email for the domain should be delivered.
• TXT stores verification and policy text such as SPF, DKIM, DMARC, and site ownership checks.
• NS identifies the authoritative nameservers for a domain.
• CAA can restrict which certificate authorities may issue SSL certificates for the domain.

How to read a DNS lookup

Start with the hostname you actually use, such as example.com or www.example.com. Check whether the returned address matches the expected hosting provider or CDN. Then review the TTL. A short TTL means resolvers should refresh the answer sooner; a long TTL can make old values appear after a change.

Why results differ

DNS answers may differ because of resolver cache, propagation timing, split DNS, CDN geolocation, DNSSEC validation, or a recent nameserver change. If a production change looks wrong, compare more than one resolver and confirm the authoritative nameserver response before making another change.

Useful next checks

Use the DNS Lookup tool for public records, the MX Record Lookup for mail routing, and the TXT Record Lookup for SPF, DKIM, DMARC, and verification records.