The Name Servers of a domain show the DNS servers that handle its DNS records. The Internet protocol address of the site (A record), the mail server that deals with the e-mails for a domain name (MX records), any text record in free form (TXT record), forwarding (CNAME record) and so forth are extracted from the DNS servers of the web hosting company and for any domain name to be using them and to be pointed to their hosting platform, it ought to have their name servers, or NS records. If you wish to open a site, for example, and you type in the URL, the web browser connects to a DNS server, which keeps the NS records for the domain name and the request is then redirected to the DNS servers of the hosting company where the A record of the website is obtained, so that you can view the content from the proper location. Commonly a domain has 2 name servers that start with NS or DNS as a prefix and the difference between the two is just visual.