Short answer
DNS is the naming system of the internet. It lets you type domain names instead of remembering IP addresses.
How a DNS lookup works
When you type an address, your device asks a DNS resolver which IP address the domain points to. The answer is often cached for a short time so the next visit is faster.
DNS and privacy
The DNS service you use can see which domains you look up. Encrypted DNS can reduce visibility on local networks, but the choice of DNS operator still matters.
DNS and security
Incorrect DNS answers can send users to the wrong place. That is why technologies such as DNSSEC, filtering DNS and security controls exist.
Common questions
Is DNS the same as web hosting?
No. DNS points to where a service is located. The web host or server delivers the content.
Can I change DNS?
Yes, you can often change DNS in your router, computer or phone, but use a provider you trust.