The NS, or Name Server records of a domain name, indicate which servers deal with the Domain Name System (DNS) records for it. Setting the name servers of a given host company for your domain 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, so if you need to change some of these records, you'll be able to do it via 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 domain name you are trying to access. That 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 each and every domain name has at least 2 NS records. There is no practical difference between the two prefixes, so what type a website hosting provider is going to use depends entirely on their preference.