The Name Servers of a domain point out the DNS servers that deal with its DNS records. The Internet protocol address of the web site (A record), the mail server that takes care of the e-mails for a domain (MX records), any text record in free form (TXT record), pointing (CNAME record) and so on are obtained from the DNS servers of the web hosting company and for any domain to be using them and to be pointed 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 type in the URL, the Internet browser connects to a DNS server, which keeps the NS records for the domain address and the request is then forwarded to the DNS servers of the hosting company where the A record of the website is retrieved, allowing you to see the content from the right location. Ordinarily a domain address has a couple of name servers that start with NS or DNS as a prefix and the contrast between the two is just visual.