The Name Servers of a domain name reveal the DNS servers that are responsible for its DNS records. The Internet protocol address of the website (A record), the mail server that handles the e-mails for a domain (MX records), any text record in free form (TXT record), forwarding (CNAME record) and so on are extracted from the DNS servers of the hosting company and for any Internet domain to be using them and to be directed to their hosting platform, it has to have their name servers, or NS records. If you wish to open a site, for instance, and you input the URL, the 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 provider where the A record of the site is obtained, so that you can look at the content from the right location. Ordinarily a domain name has two name servers that start with NS or DNS as a prefix and the difference between the two is just visual.