The Name Servers of a domain point out the DNS servers that are responsible for its DNS records. The IP address of the website (A record), the mail server that takes care of the emails for a domain name (MX records), any text record in free form (TXT record), forwarding (CNAME record) and so forth are taken from the DNS servers of the website hosting company and for any Internet domain to be using them and to be forwarded to their hosting platform, it should have their name servers, or NS records. If you would like to open an Internet site, for example, and you insert the URL, the Internet browser connects to a DNS server, which keeps the NS records for the domain name and the request is then pointed to the DNS servers of the webhosting provider where the A record of the site is obtained, so you can look at the content from the proper location. Commonly a domain name has two name servers that start with NS or DNS as a prefix and the difference between the two is only visual.