You never type a phone number to call your mum. You tap her name and your phone looks up the number. DNS does the same for every website you visit.
Nobody remembers phone numbers any more. You save “Mum” once, then tap her name. Your phone quietly finds the number and dials it.
Websites work the same way. Computers find each other using IP addresses, long numbers like 142.250.180.14. People would never remember those. DNS is the contacts list that turns a name you can remember, like google.com, into the number your device actually needs.
What happens when you visit a site
- You type laymanterms.dev.
- Your device asks a DNS service: “What’s the number for this name?”
- It replies with the IP address.
- Your device connects to that address and the page loads.
All of this usually takes a fraction of a second. Your device also remembers the answer for a while, so it doesn’t have to ask every time.
Who keeps the list
No single computer holds the whole list. DNS is spread across many servers around the world, each in charge of its own part, like a chain of directories that point to each other. Your internet provider usually runs the one your device asks first.
What it isn’t
It isn’t the website itself. DNS only says where to go. If DNS breaks, the website can be perfectly fine but nobody can find it.
Where the comparison breaks down
Your contacts are yours alone. DNS is shared by everyone. When a website moves, its entry has to be updated. That change can take a few hours to reach everybody.
How the words fit together
A domain name is the name you type. An IP address is the number behind it. DNS connects the two. Then HTTPS carries the page to you safely.
When people say “the internet is down” but some apps still work, it's often DNS. The websites are fine. Your device just can't look up where they are.
When you'll hear it
“It's always DNS.” A running joke among tech teams. When something breaks mysteriously, DNS is often the cause.
“The DNS change hasn't spread yet.” A site's address was just updated and the change is still reaching everyone. It can take a few hours.
“Switch your DNS to 1.1.1.1.” Use a different contacts-list service, which can be faster or more private than your internet provider's.
“If we move the website, how long will some people still be sent to the old address?”
Try it yourselfReady to use it? The exact commands are on my other site, devcmds: Clear the DNS cache ↗
