What is an NS record?

NS records ("name server") identify a different host to provide the DNS management for the host.

Note: Custom NS records are used to point a specific subdomain to a different set of nameservers, which can then allow you to manage DNS for the subdomain further on another DNS service. Custom NS records are used to point a specific subdomain to a different set of nameservers, which can then allow you to manage DNS for the subdomain further on another DNS service.

Here's an example of an NS record.