The Name Servers of a domain name show the DNS servers that handle its DNS records. The Internet protocol address of the 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 extracted from the DNS servers of the web hosting company and for any domain address to be using them and to be directed to their hosting platform, it needs to have their name servers, or NS records. If you want to open a website, for example, and you type in the URL, the Internet 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 provider where the A record of the web site is obtained, so you can see the content from the right location. Usually a domain address has 2 name servers that start with NS or DNS as a prefix and the contrast between the two is simply visual.