Explain like I'm five · Security

What is DNS?

The Domain Name System, told as a story about the town directory that turns names into addresses.

I want to go to the Photo Castle10.0.0.710.0.0.1210.0.0.41?you know the name, but roads only go by number

People only know names.'Photo Castle', 'Mail Castle'. But roads only go by number.

Photo10.0.0.7Mail10.0.0.12Meeting10.0.0.41market10.0.2.9library10.0.2.30the Photo Castle moved…one castle moves, and everything you memorized is wrong

You can't memorize all the numbers.And if a castle moves, everything you memorized is wrong.

DIRECTORYWhere's the Photo Castle?East 3rd St. 7Photo10.0.0.7Mail10.0.0.12Meeting10.0.0.41you only need the name; the directory knows the address

DNS is the directory that turns names into addresses.'Where's the Photo Castle?' 'East 3rd Street, number 7.' You only need the name.

The namewhat people remember
The addresswhat roads understand
The directoryasks around on your behalf
Jotting it downthe same question, answered at once
town directorycountry directory (.kr)world directorythe Photo Castle's ownno idea…no idea…no idea…East 3rd St. 7the answer is jotted down — the next person gets it at oncetown → country → world → that castle's own directory

If our directory doesn't know, it asks a bigger one.Town → country → world → that castle's own directory. The answer is jotted down for a while — like the copy depot.

DIRECTORYWhere's the Photo Castle?end of that alleyfake Photo Castlea stamp on the answerthe question sealed

If the directory lies, you walk into a fake castle.So answers get a stamp (DNSSEC) and questions travel sealed (DoH). The fake castle also shows up in the gatekeeper story.

In one breath

DNS = the town directory that turns the name 'Photo Castle' into the address 'East 3rd Street, 7'.

The Domain Name System, around since 1983. 8.8.8.8 and 1.1.1.1 are famous directories. When the directory stops, the internet looks down — the castles are fine, nobody can find them.

When grown-ups say it

Domain name
The name. Letters people remember, like photo.example.kr.
IP address
The numeric address. The number roads actually follow. → the wall with many doors
Resolver
The town directory. Asks around for me. 8.8.8.8, 1.1.1.1.
Authoritative server
That castle's own directory. The last stop, holding the real answer.
Root · TLD
World · country directories. They split the big sections: .kr, .com and so on.
TTL
How long the jotted answer lasts. Past it, ask again. → the copy depot
DNSSEC
A stamped answer. A swapped answer can be spotted.
DoH · DoT
A sealed question. Nobody on the road overhears where you're going. → the sealed tunnel
Next story
The Number-Tag Desk →
Want another term as a picture book? Request →