The Name Servers of a domain name point out the DNS servers that are responsible for its DNS records. The Internet protocol address of the site (A record), the mail server that manages the e-mails for a domain address (MX records), any text record in free form (TXT record), pointing (CNAME record) and so on are taken from the DNS servers of the hosting provider and for any domain to be using them and to be forwarded to their hosting platform, it ought to have their name servers, or NS records. If you want to open a website, for example, and you input the URL, the browser connects to a DNS server, which keeps the NS records for the domain and the request is then pointed to the DNS servers of the hosting company where the A record of the web site is obtained, so you can view the content from the correct location. Ordinarily a domain has a couple of name servers that start with NS or DNS as a prefix and the contrast between the two is only visual.