The Name Servers of a domain name show the DNS servers that deal with its DNS records. The IP of the site (A record), the mail server that handles the emails for a domain (MX records), any text record in free form (TXT record), directing (CNAME record) and so forth are obtained from the DNS servers of the hosting provider and for any Internet domain to be using them and to be pointed to their hosting platform, it should have their name servers, or NS records. If you wish to open a site, for instance, and you type in the URL, the Internet browser connects to a DNS server, which keeps the NS records for the domain and the request is then forwarded to the DNS servers of the hosting company where the A record of the web site is retrieved, so you can look at the content from the correct 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 just visual.