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 given hosting provider for your domain address is the easiest way to point it to their system and all its sub-records will be taken care of on their end. This includes A (the IP address of the server/website), MX (mail server), TXT (free text), SRV (services), CNAME (forwarding), etcetera, so, in case you would like to edit any one of these records, you're going to be able to do it through their system. Put simply, the NS records of a domain show 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 Internet domain you are attempting to reach. This way the web site that you will see will be retrieved from the right location. The name servers normally have a prefix “ns” or “dns” and each domain name has at least 2 NS records. There is absolutely no functional difference between the two prefixes, so what kind a host company will use depends completely on their preference.