Name Servers
Name servers are computer servers that implement a name service protocol. The domain name system (DNS) is a special type of name server that converts domain names into IP addresses so that the request for the domain can be directed to the appropriate web server.
When you sign up for hosting at the same time you register a domain name, the hosting company will set up the name servers for you. This simplifies the initial process, but if you ever want to switch to a different web hosting service, or want to transfer your domain name to a different registrar you will need to update the name servers.
The DNS requires 2 name servers for each domain to provide redundancy. This will be carried out in your domain control panel by specifying the name server, such as "NS1.example.com" and "NS2.example.com" where your domain is "example.com", and then assigning the web servers IP address of the web server that the domains files will be hosted on to those name servers.