The NS, or Name Server records of a domain, point out which servers deal with the Domain Name System (DNS) records for it. Setting the name servers of a specific hosting provider for your domain name is the simplest way to forward it to their system and all its sub-records are going to 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), and so forth, if you need to modify any one of these records, you will be able to do it by using their system. To put it differently, the NS records of a domain reveal 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 domain name you are attempting to reach. In this way the web site that you'll see is going to be retrieved from the proper location. The name servers typically have a prefix “ns” or “dns” and every single domain address has at least 2 NS records. There's no sensible difference between the two prefixes, so which one a host company will use depends only on their preference.