The Name Servers of a domain name show the DNS servers that handle its DNS records. The IP address of the website (A record), the mail server that deals with the emails for a domain name (MX records), any text record in free form (TXT record), pointing (CNAME record) etc are obtained from the DNS servers of the website hosting company and for any Internet domain to be using them and to be directed to their hosting platform, it needs to have their name servers, or NS records. If you want to open a site, for instance, and you insert the URL, the browser connects to a DNS server, which keeps the NS records for the domain name and the request is then sent to the DNS servers of the hosting provider where the A record of the web site is retrieved, so that you can view the content from the proper location. Commonly a domain name has 2 name servers that start with NS or DNS as a prefix and the difference between the two is simply visual.