The NS, or Name Server records of a domain, point out which servers handle 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), and so on, if you need to modify any one of these records, you'll be able to do it through their system. Put simply, the NS records of a domain name point out the DNS servers which 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 domain you are attempting to access. This way the site that you'll see is going to be retrieved from the right location. The name servers typically have a prefix “ns” or “dns” and each domain has at least 2 NS records. There is absolutely no sensible difference between the two prefixes, so which one a host company is going to use depends completely on their preference.