The Name Servers of a domain show the DNS servers that are responsible for its DNS records. The IP address of the web site (A record), the mail server that takes care of the e-mails for a domain address (MX records), any text record in free form (TXT record), forwarding (CNAME record) and so on are taken from the DNS servers of the web hosting provider 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 an Internet site, for instance, and you input the URL, the Internet browser connects to a DNS server, which keeps the NS records for the domain name and the request is then forwarded to the DNS servers of the hosting provider where the A record of the website is obtained, so that you can view the content from the correct location. Ordinarily a domain has a couple of name servers that start with NS or DNS as a prefix and the contrast between the two is only visual.