The NS, or Name Server records of a domain, indicate which servers manage the Domain Name System (DNS) records for it. Setting the name servers of a given hosting provider for your domain is the most effective 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), etc, so if you would like to edit any of these records, you will be able to do it using their system. In other words, the NS records of a domain address reveal 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 are trying to access. That way the site that you will see is going to be retrieved from the proper location. The name servers normally have a prefix “ns” or “dns” and every single domain name has at least two NS records. There isn't any functional difference between the two prefixes, so which one a hosting provider will use depends exclusively on their preference.