The NS, or Name Server records of a domain, point out which servers manage the Domain Name System (DNS) records for it. Setting the name servers of a particular hosting provider for your domain is the easiest way to direct 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), and so on, if you would like to edit some of these records, you're going to be able to do it through their system. To put it differently, the NS records of a domain point out the DNS servers that are authoritative for it, so when you try to open a web address, the DNS servers are contacted to retrieve the DNS records of the domain you are trying to access. In this way the site that you will see is going to be retrieved from the correct location. The name servers usually have a prefix “ns” or “dns” and each and every domain address has at least 2 NS records. There is no functional difference between the two prefixes, so what kind a web hosting provider will use depends exclusively on their preference.