The username is determined by you or the provider. Internet is all lower case letters. The middle level domain. A machine name is determined always by the access provider. The organization or geographical description is the top domain.
Organizational name is standard.
An IP address identifies a location within within an IP network. An IP address contains 4 pieces of information. In the example example 128.40. The two numbers in the middle are dedicated to classification of the address. A commercial institution.