The NS, or Name Server records of a domain, reveal which servers handle the Domain Name System (DNS) records for it. Setting the name servers of a given hosting provider for your domain is the simplest way to forward 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, so if you need to edit any of these records, you're going to be able to do it via 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 obtain the DNS records of the domain you are attempting to reach. In this way the web site that you will see is going to be retrieved from the proper location. The name servers typically have a prefix “ns” or “dns” and every single domain has at least 2 NS records. There is absolutely no functional difference between the two prefixes, so which one a website hosting provider will use depends only on their preference.