The NS, or Name Server records of a domain name, indicate which servers handle the Domain Name System (DNS) records for it. Setting the name servers of a specific hosting provider for your domain address is the most effective way to forward it to their system and all its sub-records will 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 on, so if you want to change some of these records, you will be able to do it via their system. In other words, the NS records of a domain name reveal 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 want to access. That way the site that you will see will be retrieved from the right location. The name servers normally have a prefix “ns” or “dns” and each and every domain name has at least 2 NS records. There's no functional difference between the two prefixes, so what kind a host company will use depends completely on their preference.