The NS, or Name Server records of a domain, indicate which servers handle 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 direct it to their system and all its sub-records will 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), and so on, so if you wish to edit any of these records, you'll be able to do it through their system. In other words, 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 attempting to reach. In this way the website that you will see will be retrieved from the right location. The name servers normally have a prefix “ns” or “dns” and every single domain address has at least two NS records. There is no practical difference between the two prefixes, so which one a web hosting provider is going to use depends exclusively on their preference.