The Name Servers of a domain name show the DNS servers that manage its DNS records. The Internet protocol address of the web site (A record), the mail server that manages the emails for a domain (MX records), any text record in free form (TXT record), forwarding (CNAME record) etc are obtained from the DNS servers of the website hosting company and for any domain name to be using them and to be forwarded to their hosting platform, it ought to have their name servers, or NS records. If you wish to open an Internet site, for instance, and you insert the URL, the web browser connects to a DNS server, which keeps the NS records for the domain and the request is then sent to the DNS servers of the hosting provider where the A record of the web site is retrieved, allowing you to view the content from the proper location. Usually a domain address has a couple of name servers that start with NS or DNS as a prefix and the difference between the two is simply visual.