DNS: The Invisible System Behind Every Click

The 30-second explanation

DNS is basically the internet's phonebook. You type google.com and DNS helps your computer find where Google lives.

How it works

1. 1

   1. You type a name

   Your browser asks: where is example.com?

2. 2

   2. Resolver checks

   It checks its cache, then asks other servers.

3. 3

   3. Authoritative answer

   The domain's official server returns the address.

4. 4

   4. You connect

   Your browser connects to the returned address.

Computers find each other with numbers called IP addresses, but people prefer names. DNS is the system that translates one into the other. When you type a website name, your device asks a DNS server where that name lives, and the server answers with an address in a fraction of a second. Because so much starts with a DNS lookup, it is also a useful place for defenders to watch — a strange, never-seen-before name being requested can be an early clue something is wrong.

Real-world example

How to spot it

• A name that looks almost right

  Lookalike domains swap a letter or add a word to a trusted name.

• A brand-new domain

  Names registered very recently are disproportionately used in scams.

• Unusually long subdomains

  Long, random-looking prefixes can be a sign of automated or hidden traffic.

• A padlock that means less than it looks

  A secure connection only proves encryption, not that the site is trustworthy.

What to do

1. 1Type addresses you trust directly rather than following links for sensitive sites.
2. 2Double-check a domain letter by letter before entering a password on it.
3. 3If a device asks for a domain no one recognises, treat it as worth investigating, not ignoring.