What is DNS?
This guide covers the difference between a domain, a nameserver and a DNS record, and what propagation and TTL mean when you change a setting.
The Domain Name System (DNS) is the internet's address book. It turns a name such as example.com into the places where its services live. When a visitor opens your site, the browser asks DNS where to go.
These terms are easy to mix up:
- Domain: the name you register, such as
example.com. You rent it for a period. - Nameserver: the server that holds the DNS records for your domain. A domain points to its nameservers. Changing nameservers changes where all of your DNS records are managed.
- DNS record: one setting in the zone, such as an A record for the website address or an MX record for email. Records are the settings you usually change.
- Propagation: the time it takes for a change to spread across the internet. Some networks update quickly and others take longer.
- TTL (time to live): a number, in seconds, that tells other servers how long to remember a record before they check again. A lower TTL means changes spread faster, but it can increase the number of lookups.
Adding one record is different from changing nameservers. Most changes, such as adding an A record or an MX record, do not need new nameservers. Read Find your DNS provider to see where your records should be edited.
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Last reviewed
2026-10-27