Complex sentence: A user often has a user account and is identified by a username (also user name), screen name (also screenname), nickname (also nick), or handle, which is derived from the identical Citizen's Band radio term.
Split into simpler sentences: A user often has a user account and is identified by a username (also user name). Other terms for username include login name, screen name (also screenname), nickname (also nick), or handle, which is derived from the identical Citizen's Band radio term.