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 particular host company for your domain is the most effective way to direct 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), and so on, so if you need to edit some of these records, you'll be able to do it via their system. Put simply, the NS records of a domain address point out the DNS servers which 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 you are attempting to access. This way the web site that you'll see will be retrieved from the proper location. The name servers normally have a prefix “ns” or “dns” and every single domain address has at least 2 NS records. There isn't any practical difference between the two prefixes, so what type a hosting provider will use depends exclusively on their preference.