What is a name server?#
A name server (NS) is where your domain's list of DNS records lives. When a browser asks where a domain is, the answer ultimately comes from these servers.
How is it like an address?#
You register the domain with a registrar, but you may manage the records somewhere else. The name server says "read this domain's settings from here".
Typical form#
Name servers usually come in twos or more, such as ns1.example.net and ns2.example.net. Several are registered for reliability, so that if one fails, another answers.
When do you change them?#
- When moving hosting, if the new host gave you its own name servers
- When using an external DNS or CDN service
- When connecting to a service that takes over full management of the domain
An important note#
If you change the name servers, the records on the old name servers no longer take effect. You must create the needed records, such as A, MX and TXT, at the new place too, or email and subdomains will stop working.
How to change them#
From the domain registrar's panel, in the DNS or name server management section. The change can take from a few hours to about a day.
Common mistake#
Changing name servers without copying the email records. The result is that business email stops working.