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 particular host company for your domain address is the easiest way to forward 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 want to change any of these records, you'll be able to do it via their system. To put it differently, the NS records of a domain name show the DNS servers that are authoritative for it, so when you try to open a web address, the DNS servers are contacted to get the DNS records of the Internet domain you want to access. In this way the website that you will see will be retrieved from the right location. The name servers usually have a prefix “ns” or “dns” and each domain name has at least 2 NS records. There isn't any sensible difference between the two prefixes, so what type a website hosting provider is going to use depends exclusively on their preference.