The NS, or Name Server records of a domain name, reveal which servers handle the Domain Name System (DNS) records for it. Setting the name servers of a specific hosting provider for your domain name is the most convenient way to direct 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, so if you would like to edit any of these records, you will be able to do it through their system. To put it differently, the NS records of a domain name reveal 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 domain you are trying to reach. In this way the site that you'll see is going to be retrieved from the proper location. The name servers usually have a prefix “ns” or “dns” and each domain address has at least two NS records. There isn't any practical difference between the two prefixes, so which one a host company is going to use depends exclusively on their preference.