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 specific hosting provider for your domain name is the easiest way to direct it to their system and all its sub-records will be taken care of 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 would like to edit some of these records, you're going to be able to do it through their system. Put simply, the NS records of a domain name point out the DNS servers that are authoritative for it, so when you try to open a web address, the DNS servers are contacted to retrieve the DNS records of the domain name you are trying to access. That way the website you will see is going to 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 two NS records. There is absolutely no sensible difference between the two prefixes, so what type a web hosting provider is going to use depends only on their preference.