The NS, or Name Server records of a domain, show 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 easiest way to forward 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), etcetera, so, in case you want to edit any of these records, you are going to be able to do it by using their system. In other words, the NS records of a domain show the DNS servers which are authoritative for it, so when you attempt to open a web address, the DNS servers are contacted to obtain the DNS records of the domain name you are attempting to access. In this way the web site you will see will be retrieved from the right location. The name servers typically have a prefix “ns” or “dns” and each domain address has at least 2 NS records. There isn't any sensible difference between the two prefixes, so what type a hosting provider will use depends exclusively on their preference.