The NS, or Name Server records of a domain name, show which servers deal with the Domain Name System (DNS) records for it. Setting the name servers of a particular hosting provider for your domain is the most convenient way to point it to their system and all its sub-records will be handled on their end. This includes A (the IP address of the server/website), MX (mail server), TXT (free text), SRV (services), CNAME (forwarding), and so on, if you need to modify any of these records, you're going to be able to do it via their system. Put simply, the NS records of a domain show the DNS servers which are authoritative for it, so when you attempt to open a web address, the DNS servers are contacted to obtain the DNS records of the Internet domain you are trying to reach. That way the site that you'll see is going to be retrieved from the correct location. The name servers typically have a prefix “ns” or “dns” and each domain address has at least 2 NS records. There is absolutely no functional difference between the two prefixes, so what type a web hosting provider will use depends only on their preference.