The information in both a postal address and an email address is presented in order from the most specific to the most general. In a postal address, this sequence is top to bottom (addressee, street, city, state, country), while in an email address it is left to right, as shown here and explained below:

username@node.domain.extension.cc

• username
  (also known as login, loginID, handle, or account) is the unique network "name" of an individual at a particular location. At NC State, your username is your Unity ID.
• node
  The name of the computer or computer system on which an individual has an account. Unity is one of the many nodes at NC State. You can use the shortened format for your address that does not include the node; i.e., unityid@ncsu.edu instead of unityid@unity.ncsu.edu.
• domain
  Usually the name of the organization that manages the computer or node. In your case the domain is ncsu. Often a domain will have more than one part.
• extension
  An abbreviation for the kind of organization that maintains the computer. NC State's domain extension is edu, used by all educational institutions. Other extensions include com (commercial), gov (governmental), mil (military), net (network), and org (organization).
• cc
  The country code. This is not used in a campus email address. It is included in a person's email address only when a country's Internet domain is being used.