Also known as a JID, is the unique identifier of a Jabber Messenging system. Similar to an email address, it is the means by which users and Jabber software locate the appropriate service and user for attempted communication.
Unlike commercial Public Im services such as AIM, ICQ, Msn Messenger, and Yahoo Messenger, there is more than one instance of the Jabber service. In this decentralized model, anyone can put up a Jabber server that can communicate with other Jabber servers similar to the way e-mail is handled.
APU now has its own Jabber service, hosted at apuim.apu.edu. Which means JID's for this service are
!üdeupa_username@apuim.apu.edu.
Other Jabber services can be found on the jabber.org website