The NS, or Name Server records of a domain name, show which servers handle the Domain Name System (DNS) records for it. Setting the name servers of a particular hosting provider for your domain address is the simplest way to point it to their system and all its sub-records are going to be handled 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 need to change any of these records, you are going to be able to do it via their system. In other words, the NS records of a domain address reveal the DNS servers that are authoritative for it, so when you try to open a web address, the DNS servers are contacted to obtain the DNS records of the domain you are attempting to reach. This way the web site that you'll see will be retrieved from the proper location. The name servers usually have a prefix “ns” or “dns” and each domain has at least 2 NS records. There is absolutely no functional difference between the two prefixes, so what type a web hosting provider will use depends completely on their preference.