The Name Servers of a domain reveal the DNS servers that handle its DNS records. The Internet protocol address of the site (A record), the mail server that manages the e-mails for a domain (MX records), any text record in free form (TXT record), forwarding (CNAME record) etc are taken from the DNS servers of the web hosting provider and for any domain address to be using them and to be directed to their hosting platform, it ought to have their name servers, or NS records. If you want to open a website, for example, and you type 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 company where the A record of the site is obtained, enabling you to look at the content from the right location. Ordinarily a domain address has two name servers that start with NS or DNS as a prefix and the distinction between the two is only visual.