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Definition
DNS, short for Domain Name System, is the system that translates a domain name such as example.com.au into the technical records computers need to find websites, deliver email and connect online services.
DNS is often described as the phonebook of the internet, but it does more than point a domain to a website. It also controls email routing, verification records, SSL/TLS validation and many third-party service connections.
Key Takeaways
- DNS connects a domain name to websites, email platforms and other online services.
- Incorrect DNS changes can take a website offline, stop email delivery, break forms or interrupt third-party tools.
- DNS should be reviewed before website launches, hosting migrations, email changes and domain transfers.
Plain English Explanation
Why DNS Matters More Than Most Businesses Realise
How It Works
What Happens When Someone Visits Your Website
The DNS lookup process happens quickly, often in milliseconds. The basic journey can be understood in three stages.
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The browser asks where the domain lives
When a visitor enters your domain name, their device asks a DNS resolver for the records attached to that domain. The resolver is often provided by the visitor’s internet provider or a public DNS service.
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DNS finds the authoritative answer
If the resolver does not already have a recent answer cached, it follows the DNS chain to find the authoritative nameservers for the domain. These nameservers hold the active DNS zone records.
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The visitor is directed to the right service
The resolver returns the relevant DNS record, such as an A record for a website or an MX record for email. The visitor’s browser or email server then connects to the destination listed in that record.
Important DNS Terms Explained
DNS uses technical terms that can sound similar. These are the terms business owners are most likely to encounter during a website launch, email setup or migration.
- Nameservers
- Nameservers tell the internet where the active DNS records for a domain are managed. If nameservers point to the wrong provider, the records you edit elsewhere may not affect the live domain.
- DNS Zone
- A DNS zone is the collection of records for a domain. It may include records for the website, email, verification services, security policies and third-party platforms.
- TTL
- TTL means time to live. It tells DNS resolvers how long they can cache a record before checking for a fresh answer. Shorter TTL values can help during planned changes, but they should still be managed carefully.
DNS Records
The Main Types of DNS Records
Example DNS Zone
This simplified example shows how different records can work together for one domain. The values are examples only and should not be copied into a live DNS zone.
example.com.au. A 203.0.113.10
www.example.com.au. CNAME example.com.au.
example.com.au. MX 10 mail.example-email-provider.com.
example.com.au. TXT "v=spf1 include:example-email-provider.com ~all"A simple DNS zone may include website, www, email and authentication records.
DNS, Domains and Hosting Are Not the Same Thing
Many website and email problems start because these three terms are used interchangeably. They are connected, but they do different jobs.
| Area | What It Does | Business Impact |
|---|---|---|
| Domain name | The registered name people use to find your business online, such as yourbusiness.com.au. | If ownership or renewal access is unclear, your website and email may be at risk. |
| DNS | The instruction layer that tells browsers, mail servers and platforms where to send traffic. | Incorrect records can break websites, email, SSL/TLS validation and third-party integrations. |
| Website hosting | The server environment where your website files, application and database are stored. | Poor hosting can affect speed, uptime, security and user experience, even if DNS is correct. |
DNS Can Affect Both Your Website and Email
Business Impact
How DNS Affects Websites, Email and Online Services
Registrar DNS vs Managed DNS
Potential Advantages of Basic Registrar DNS
- It may be simple for a small domain with only a basic website record and no complex email or platform connections.
- It is often included with domain registration, so there may be no separate DNS management interface to learn.
- It can be adequate when the domain is low-risk, well documented and not tied to critical business systems.
Reasons Managed DNS May Be Preferred
- Managed DNS can provide stronger oversight when websites, email, SSL/TLS, security services and third-party tools all depend on the same domain.
- A managed approach can reduce provider finger-pointing because one technical contact can review records in context.
- Platforms such as Cloudflare can support fast DNS resolution, DDoS protection and SSL/TLS management when configured correctly.
Common DNS Mistakes to Avoid
DNS changes are not always difficult, but mistakes can be disruptive. These are common problems we see during launches, migrations and email changes.
Changing nameservers without copying existing records
Do this instead
Before changing nameservers, export or document the current DNS zone. Recreate required website, email, verification and authentication records in the new DNS provider before cutover.
Deleting email records during a website launch
Do this instead
Treat website and email records separately. Moving a website usually requires changes to web records, not the removal of MX, SPF, DKIM or DMARC records.
Assuming DNS updates are instant everywhere
Do this instead
Allow for DNS propagation and caching. Lowering TTL values before planned changes may help, but some networks and devices may still use cached records for a period of time.
Common DNS Problems and What They May Mean
These symptoms do not always prove DNS is the only cause, but they are strong signals that DNS should be checked.
The website is not loading after a launch or migration
Likely cause
The domain may still point to the old server, the A record may be wrong, or DNS propagation may still be occurring.
Solution
Check the live nameservers, confirm the active A or CNAME record, verify the hosting server is ready, and allow for propagation where appropriate.
Business emails are bouncing or not arriving
Likely cause
MX records may be missing or pointing to the wrong mail provider. SPF, DKIM or DMARC records may also be incomplete.
Solution
Review mail routing records and email authentication records together. If the business uses Microsoft 365 or another provider, confirm the records match that provider’s current requirements.
A third-party platform cannot verify the domain
Likely cause
The required TXT or CNAME verification record may be missing, entered in the wrong place or cached by DNS resolvers.
Solution
Confirm the record name, value and active DNS provider. Then test again after allowing enough time for the record to become visible.
DNS Review Checklist Before Making Changes
Use this checklist before changing DNS for a website launch, hosting migration, email migration or domain transfer.
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Confirm where DNS is currently managed
Check the active nameservers first. Editing records at the registrar will not help if the domain uses DNS from another provider.
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Document all existing records
Record website, www, email, SPF, DKIM, DMARC, verification and third-party service records before making changes.
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Plan the timing and rollback path
Avoid making critical changes without knowing how to restore the previous records if something fails during cutover.
DIY or Support
Can You Manage DNS Yourself?
Our Approach
How We Manage DNS at Dobble
DNS FAQs
These short answers clarify common DNS questions that come up during website launches, email setup and provider changes.
Is DNS the same as a domain name?
How long do DNS changes take?
Can DNS affect SEO?
Need a DNS or Domain Review?
If you are launching a website, moving hosting, changing email providers or trying to untangle an old domain setup, we can review your DNS and help plan the next step with less guesswork.