The NS, or Name Server records of a domain name, reveal which servers deal with the Domain Name System (DNS) records for it. Setting the name servers of a given hosting provider for your domain address is the most effective way to forward it to their system and all its sub-records are going to 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), etc, if you need to edit any one of these records, you will be able to do it through their system. In other words, the NS records of a domain name point out the DNS servers which are authoritative for it, so when you try to open a web address, the DNS servers are contacted to obtain the DNS records of the Internet domain you want to access. This way the website that you're going to see is going to be retrieved from the right location. The name servers usually have a prefix “ns” or “dns” and each domain address has at least two NS records. There is absolutely no functional difference between the two prefixes, so what kind a website hosting provider will use depends completely on their preference.