This is the owner of the domain name. It should be the individual or company that 'owns' the domain name. This normally is the individual or role that takes care of your web page. Here is where your web designer might be listed. The web designer should have a valid email address, phone number, and name to register.
Fax numbers are optional input.
It can just as well be your web designer but is more commonly listed as Sound.net. This listing also needs a valid email address, phone number, and name to register. Fax numbers are optional input. This billing contact should also have a valid email address. The billing information is sent through email to this contact.