The Name Servers of a domain point out the DNS servers that deal with its DNS records. The Internet protocol address of the website (A record), the mail server that takes care of the emails for a domain address (MX records), any text record in free form (TXT record), directing (CNAME record) and so forth are obtained from the DNS servers of the website hosting company and for any domain address to be using them and to be pointed to their hosting platform, it should have their name servers, or NS records. If you want to open an Internet site, for example, and you enter the URL, the browser connects to a DNS server, which keeps the NS records for the domain and the request is then sent to the DNS servers of the hosting provider where the A record of the website is obtained, allowing you to look at the content from the proper location. Normally a domain has two name servers that start with NS or DNS as a prefix and the contrast between the two is simply visual.