A user account that lacks permissions, and is temporary is typically a guest account. These accounts have minimal access.
A user is a person who utilizes a computer or network service.
A user often has a user account and is identified to the system by a username (or user name). Other terms for username include login name, screenname (or screen name), account name, nickname (or nick) and handle, which is derived from the identical citizens band radio term.
Some software products provide services to other systems and have no direct end users.