NS record
An NS (Nameserver) record identifies which servers are authoritative for a domain -- the servers that hold the actual DNS records and answer queries about that domain, as opposed to servers that merely cache or forward answers. NS records exist both at the domain's registrar (delegating the domain to its DNS provider) and within the DNS zone itself, and the two sets should match; a mismatch can cause intermittent resolution failures. Changing DNS providers means updating NS records at the registrar, and because of DNS caching and TTLs, that change can take time to propagate fully across resolvers worldwide rather than applying instantly.
By AdminKit team, Netbase JSC · Updated