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 hosting provider for your domain is the easiest way to forward 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 forth, so, in case you want to edit some of these records, you are going to be able to do it using their system. To put it differently, the NS records of a domain address reveal the DNS servers which are authoritative for it, so when you try to open a web address, the DNS servers are contacted to get the DNS records of the Internet domain you are attempting to reach. This way the website you'll see is going to be retrieved from the proper location. The name servers typically have a prefix “ns” or “dns” and each and every domain has at least two NS records. There is no sensible difference between the two prefixes, so which one a host company will use depends solely on their preference.