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 specific host company for your domain address is the most convenient 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, in case you would like to edit some of these records, you'll be able to do it using their system. In other words, the NS records of a domain name 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 get the DNS records of the Internet domain you want to reach. This way the website that you're going to see will be retrieved from the correct location. The name servers usually have a prefix “ns” or “dns” and every single domain address has at least two NS records. There is absolutely no functional difference between the two prefixes, so what type a hosting provider will use depends entirely on their preference.