The NS, or Name Server records of a domain, show which servers deal with the Domain Name System (DNS) records for it. Setting the name servers of a specific hosting provider for your domain name is the simplest way to direct it to their system and all its sub-records are going to 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 forth, so, in case you would like to edit some of these records, you'll be able to do it via their system. In other words, the NS records of a domain name 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 get the DNS records of the domain name you want to access. In this way the web 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 two NS records. There isn't any practical difference between the two prefixes, so which one a web hosting provider is going to use depends solely on their preference.