The Name Servers of a domain name point out the DNS servers that manage its DNS records. The IP of the site (A record), the mail server that manages the emails for a domain address (MX records), any text record in free form (TXT record), directing (CNAME record) and so on are obtained from the DNS servers of the website hosting company and for any domain address to be using them and to be forwarded to their hosting platform, it has to have their name servers, or NS records. If you would like to open a website, for example, and you enter the URL, the Internet 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 website is retrieved, enabling you to view the content from the correct location. Normally a domain has two name servers that start with NS or DNS as a prefix and the difference between the two is simply visual.