DNS records

What are DNS records?

DNS records are settings that tell the Domain Name System where a domain’s website, email, and services connect. Stored in a DNS zone on authoritative nameservers, they map names to destinations, instructions, or verification details. They are technical settings, not website content.

How DNS records work during a DNS lookup

A DNS lookup finds the record needed to reach a service.

1. A browser or app requests a domain, such as example.com.
2. A recursive DNS server checks its cache.
3. If needed, it asks the authoritative nameserver for the domain’s DNS zone.
4. The nameserver returns the needed record, such as an A record with an IP address.
5. The browser connects to the service. Tools such as nslookup can query records directly.

Common DNS record types and examples

Different record types handle routing and security.

DNS records example: connecting a website and email

A site might use an A record for example.com, an AAAA record for IPv6, and a CNAME for www. MX records route mail, while TXT records verify the domain and publish email authentication policies. A hostname normally cannot have a CNAME with other records because the alias must be the sole answer for that label.

Benefits of well-managed DNS records

Good DNS management improves reliability and security.

• Routes visitors to web applications.
• Allows infrastructure changes without changing the public domain.
• Supports email delivery and domain ownership verification.
• Enables CAA and email authentication controls.
• Can provide redundancy through multiple supported endpoints.

Practical limits and common DNS record mistakes

Caches and small errors can cause outages.

• Propagation is cache expiry, not an instant worldwide update.
• A low TTL speeds changes but increases lookup traffic.
• Wrong hostnames, duplicate values, and conflicts can break routing.
• Changing nameservers before copying the full zone can remove services.
• Weak DNS account security can let attackers redirect traffic or email.

How to check and update DNS records safely

Use a controlled process for DNS changes.

1. Identify the provider hosting the authoritative nameservers.
2. Document existing records before editing.
3. Confirm the provider’s hostname, priority, and verification instructions.
4. Lower the TTL before a planned migration when appropriate.
5. Make one change at a time.
6. Run nslookup example.com against authoritative and public resolvers.
7. Test the website, HTTPS, and email flow, then restore a normal TTL.

DNS records in application deployment

Production deployments often need DNS for custom domains, API subdomains, certificate validation, and third-party services. When building with an AI web app builder, include DNS in the release checklist alongside testing and deployment. Emergent helps teams build and ship applications, while DNS records connect the finished product to its public domain. Learn more about app design and development.