NS Record

Name server records determine which servers will communicate DNS information for a domain. Two NS records must be defined for each domain. Generally, you will have a primary and a secondary name server record - NS records are updated with your domain registrar and will take 24-72 hours to take effect.
If your domain registrar is separate from your domain host, your host will provide two name servers that you can use to update your NS records with your registrar.
If you're not sure who is hosting your domain, you can perform a free NS Lookup. Here's how:

1. Visit Google.com.
2. Search for NS lookup.
3. Select a search result.
4. Type your domain name into the tool.
5. Select NS records or Any records for your query.
6. Click Look it up.

Example result (showing that name-services.com is the domain host for mightydinosaur.com):
mightydinosaur.com nameserver = dns1.name-services.com.
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