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 host company for your domain is the easiest way to forward it to their system and all its sub-records are going to 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 if you need to change any one of these records, you will be able to do it via their system. In other words, the NS records of a domain name 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 access. In this way the web site that you're going to see is going to be retrieved from the correct location. The name servers normally have a prefix “ns” or “dns” and each and every domain has at least two NS records. There isn't any functional difference between the two prefixes, so what kind a web hosting provider is going to use depends only on their preference.