What is DNS?
A plain-English explanation of the Domain Name System — how it works, why it matters, and what it has to do with your website and email.
- Difficulty
- Beginner
Every time someone visits your website, something invisible happens in the background. Their browser needs to find out exactly where your site lives on the internet. That process is handled by DNS — the Domain Name System. This guide explains what DNS is and why it matters for your business.
Quick summary
DNS is like the internet's phone book. It translates your domain name (like yourbusiness.com) into a number that computers use to find your website or deliver your email. When you move your website or change email providers, you update DNS records to point everything to the right place.
The simple version
Computers on the internet don't understand names like yourbusiness.com. They communicate using numbers called IP addresses (for example, 203.0.113.10). DNS is the system that translates one into the other.
Think of it like a contact list on your phone. You press "Call Mum" and your phone looks up her number. DNS does the same thing — you type a domain name and DNS looks up the IP address.
How a DNS lookup works
When someone visits your website, here's what happens behind the scenes:
The browser asks a DNS resolver. Your internet provider (or a service like Cloudflare or Google) runs a DNS resolver that handles lookups.
The resolver works its way to the authoritative nameserver. If the answer isn't already in its cache, the resolver starts at the internet's root servers, gets pointed to the servers for your extension (.com, say), and is pointed from there to your domain's authoritative nameservers — the servers that hold the official DNS records for your domain.
The nameserver returns the answer. It tells the resolver: "This domain's IP address is 203.0.113.10."
The browser connects to that IP address. Your website loads.
This whole process takes milliseconds. You never see it happen.
Four hops, all of them in milliseconds. The resolver is the one that remembers — which is why a record you changed this morning can still be invisible to some visitors this afternoon, until its TTL expires.
Read this as text
When somebody types your domain, their browser does not know where your site is. It asks a DNS resolver— run by their internet provider, or by a service like Cloudflare or Google.
If the resolver does not already know the answer, it asks your domain’s authoritative nameservers, which hold the official records for your domain. They reply with the IP address, for example 185.199.108.153.
The browser then connects straight to that address and your site loads. The nameservers are not involved again.
The resolver keeps that answer for a set period, the TTL. Until it expires, that resolver keeps handing out the old answer without asking your nameservers again — which is the whole reason a DNS change can take minutes for one person and hours for another.
What are DNS records?
DNS records are the individual instructions stored on your nameserver. Each record tells the internet something specific about your domain:
| Record type | What it does |
|---|---|
| A record | Points your domain to an IP address (your website server) |
| CNAME | Points one domain or subdomain to another domain name |
| MX | Directs email for your domain to your email provider |
| TXT | Stores text-based verification and security information |
See DNS records explained for a full guide to each type.
What are nameservers?
Nameservers are the servers that hold your DNS records. When someone looks up your domain, DNS knows to ask your nameservers for the answer. Your domain is pointed to a set of nameservers at your registrar, your host, or a service like Cloudflare.
Changing your nameservers points all DNS control to a new location. Changing individual DNS records makes smaller, targeted changes. See Nameservers vs DNS records for when to do each.
Why DNS changes take time
When you update a DNS record, the change doesn't happen everywhere instantly. DNS servers around the world cache (store) records for a set period — called the TTL (Time To Live). Until that cache expires, some visitors may still see the old setting.
This delay is called DNS propagation, and the record's TTL is what mostly governs how long it lasts. For a change of nameservers, which is the slowest kind, registrars commonly tell you to allow 24 to 48 hours. See DNS propagation: why changes take time.
What DNS has to do with email
Your email also relies on DNS. MX records tell the internet which servers handle email for your domain. SPF, DKIM, and DMARC records are authentication records: they let a receiving mail server check that a message claiming to come from your domain really did, which is also what keeps your genuine mail out of the spam folder.
See Email DNS records for a full explanation.
Common questions
Do I need to understand DNS to run my website?
Not in detail — that's what we're here for. But knowing the basics helps you understand why changes sometimes take time and why we ask for access to your DNS settings.
Where are my DNS records managed?
Usually at your domain registrar (like GoDaddy or Namecheap), or at a DNS management service like Cloudflare if your domain's nameservers have been pointed there. See How to find where your domain is registered.
Can bad DNS settings break my website or email?
Yes. Incorrect DNS records can make your site unreachable or stop email from arriving. That's why we always double-check records before making changes. See Common DNS problems & fixes.
What is a DNS TTL?
TTL stands for Time To Live. It's a number (in seconds) that tells DNS servers how long to cache a record before asking for a fresh copy. Lower TTL = changes spread faster. Higher TTL = less load on DNS servers.
Related guides
- DNS records explained (A, CNAME, MX, TXT)
- Nameservers vs DNS records
- DNS propagation: why changes take time
- Email DNS records (MX, SPF, DKIM, DMARC)
- Common DNS problems & fixes
- What is a domain name? — the piece before DNS
- How DNS & hosting fit together — the piece after DNS
- Give us access to manage your DNS
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