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 given hosting provider for your domain is the easiest way to point 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 on, so if you need to edit any of these records, you're going to be able to do it through their system. In other words, the NS records of a domain name show 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 you are trying to access. That way the website that you're going to see will be retrieved from the proper location. The name servers usually have a prefix “ns” or “dns” and each domain has at least two NS records. There isn't any functional difference between the two prefixes, so what type a host company is going to use depends completely on their preference.