The NS, or Name Server records of a domain name, point out which servers handle the Domain Name System (DNS) records for it. Setting the name servers of a particular host company for your domain name is the easiest way to direct 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 forth, if you wish to change some of these records, you are going to be able to do it through their system. In other words, the NS records of a domain name point out the DNS servers that 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 Internet domain you are trying to reach. In this way the web site that you're going to see is going to be retrieved from the proper location. The name servers typically have a prefix “ns” or “dns” and every single domain name has at least 2 NS records. There is absolutely no sensible difference between the two prefixes, so what kind a website hosting provider is going to use depends solely on their preference.