The NS, or Name Server records of a domain, reveal which servers deal with the Domain Name System (DNS) records for it. Setting the name servers of a specific host company for your domain name is the easiest way to point it to their system and all its sub-records are going to be managed on their end. This includes A (the IP address of the server/website), MX (mail server), TXT (free text), SRV (services), CNAME (forwarding), etc, so if you wish to change any of these records, you are going to be able to do it via their system. In other words, the NS records of a domain reveal the DNS servers that are authoritative for it, so when you attempt to open a web address, the DNS servers are contacted to retrieve the DNS records of the Internet domain you are attempting to access. This way the site you will see is going to be retrieved from the right location. The name servers typically have a prefix “ns” or “dns” and each and every domain address has at least two NS records. There's no functional difference between the two prefixes, so what type a website hosting provider will use depends exclusively on their preference.