The NS, or Name Server records of a domain name, point out which servers handle the Domain Name System (DNS) records for it. Setting the name servers of a particular host company for your domain address is the simplest way to direct 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 forth, so if you want to edit some 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 address show 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 domain name you are trying to access. That way the website that you're going to see is going to be retrieved from the proper location. The name servers typically have a prefix “ns” or “dns” and each domain has at least two NS records. There's no sensible difference between the two prefixes, so what type a web hosting provider is going to use depends entirely on their preference.