DNS explained: how a domain name becomes a website
You type a name, a website appears. In between is DNS — the address book of the internet — doing a job most people never think about until it breaks. Here is how it works.
DNS turns a human-friendly name like example.com into the numeric address computers actually use to find each other. It's the internet's address book. A handful of record types do most of the work, and changes can take a while to spread because answers are cached along the way.
Computers don't talk to "example.com". They talk to IP addresses — strings of numbers no one wants to memorize. DNS, the Domain Name System, is the translation layer that lets you use names while the machines use numbers. Every single web visit starts with a quiet DNS lookup you never see.
What happens when you type a domain
Your browser asks "where is example.com?"
It checks its own memory first, then asks a resolver — usually run by your ISP or a service like a public DNS provider.
The resolver hunts down the answer
If it doesn't already know, it works its way up the chain to the authoritative servers that hold the real records.
It gets back an IP address
"example.com lives at this address." The browser connects there and the page loads.
Everyone caches the answer
To avoid repeating all that, the answer is remembered for a while — which is why changes aren't instant.
The records worth knowing
| Record | What it does |
|---|---|
| A | Points a name to an IPv4 address |
| AAAA | Points a name to an IPv6 address |
| CNAME | Points a name to another name (an alias) |
| MX | Says where the domain's email should go |
| TXT | Holds notes — verification, email security, and more |
Pointing a domain at a CDN usually means setting an A record or a CNAME so the name resolves to the edge network instead of straight to your origin. That one change is what puts the CDN in front of your site.
This is why DNS changes "take time". The old answer is cached all over the internet for as long as its TTL says. Lower the TTL before a planned change so the new record spreads quickly when you flip it.
Why it sometimes feels slow
That caching is a feature, not a bug — it's why the web isn't constantly re-asking the same questions. But it means a freshly changed record can take anywhere from minutes to a day to be seen everywhere, depending on the TTL you set. Plan migrations around it and it's never a surprise.
DNS is the address book that turns names into numbers so every web request can find its destination. A few record types do most of the work, pointing your domain at a CDN is usually one of them, and changes spread at the speed of caching — so lower your TTL before you move things and the rest takes care of itself.
See how NordicCDN does this for your site:
Mads has worked in IT — mostly hosting — since he was 16. He took an early stake in a SaaS company and helped grow it through to its acquisition by Visma, has built and run data-center networks, and served as CTO of a Danish data center. He started NordicCDN to make fast, secure infrastructure simple to use.
