You already buy a domain but forgot how to set name server or you switch to new hosting or you just bought a complete website and need to transfer to your hosting company then you need to know how to set name server.
Name Server Format
If you bought a hosting package (shared hosting or reseller hosting) then you should get email with details. Pay attention to these section :
(example below from certifiedhosting)
Nameserver 1 and nameserver 2 is your friend.
Login to your Domain Registrar
I use namecheap as example. The interface is clean and easy to understand.
Click on “View” link near “number of domains in your account”.
Click Domain name followed by click “Transfer DNS to a Webhost”.
Choose “Specify Custom DNS Servers” and enter value of DNS Servers.
If your web hosting package list till 4 dns servers then you must enter all servers.
Click Save Changes.
Checking DNS Change
You can use intodns.com to track the change you made.
In general any changes to name server will be affected to all internet zone take time (3 days in average, no need to worry if you can not see anything during that moment).