The Name Servers of a domain name show the DNS servers that deal with its DNS records. The Internet protocol address of the website (A record), the mail server that deals with the emails for a domain (MX records), any text record in free form (TXT record), forwarding (CNAME record) etc are obtained from the DNS servers of the hosting company and for any domain to be using them and to be forwarded to their hosting platform, it should have their name servers, or NS records. If you wish to open a website, for example, and you type the URL, the web browser connects to a DNS server, which keeps the NS records for the domain name and the request is then pointed to the DNS servers of the hosting company where the A record of the site is retrieved, so that you can see the content from the proper location. Normally a domain address has two name servers that start with NS or DNS as a prefix and the contrast between the two is only visual.