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 specific host company for your domain is the most effective way to forward it to their system and all its sub-records will 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), etc, so, in case you want to modify some of these records, you'll be able to do it through their system. To put it differently, the NS records of a domain address show 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 trying to access. In this way the web site you will see will be retrieved from the correct location. The name servers normally have a prefix “ns” or “dns” and every single domain name has at least two NS records. There is absolutely no practical difference between the two prefixes, so what type a host company is going to use depends solely on their preference.