The NS, or Name Server records of a domain, reveal which servers manage the Domain Name System (DNS) records for it. Setting the name servers of a specific host company for your domain address is the easiest way to forward it to their system and all its sub-records will 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), etc, so, in case you want to edit any of these records, you're going to be able to do it using their system. In other words, the NS records of a domain 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 get the DNS records of the Internet domain you are trying to access. This way the web site you'll see will be retrieved from the proper location. The name servers normally have a prefix “ns” or “dns” and each domain name has at least 2 NS records. There isn't any sensible difference between the two prefixes, so what kind a web hosting provider will use depends completely on their preference.