okay,im a designer,i know little about backend,but a friend of mine asked me how does cpanel /client loggin work ,how does he connect it to his servers?

Hi
I believe CPanel is a package script that comes bundled with WebHostManager to allow admin to separate each account for there users.

You need to purchase a license and install the program before you can run it. I think it basically pulls the information from a database and displays it to in cPanel depending upon the username and password entered.

More details will be at there site: http://www.cpanel.net/