Users in a computing context refers to one who uses a computer system. Users may need to identify themselves for the purposes of accounting, security, logging and resource management. In order to identify oneself, a user has an account (a user account) and a username, and in most cases also a password (see below). Users employ the user interface to access systems.

Users are also widely characterized as the class of people that uses a system without complete technical expertise required to fully understand the system. In most hacker-related contexts, they are also divided into lusers and power users. Both are terms of opprobriation, but the latter connotes a "know-it-all" attitude. See also End-user (computer science).

Screen names (also called a handle, nickname, or nick on some systems) refer to a public name that can be used to 'screen' one's true user name from the public eye. Services such as AOL allowed customers to have multiple screen names per user name, and IRC nicks are independent of one's system account username. The term "handle" (used as an alias or nickname) has derived from the identical Citizen's Band radio term.

Semantics

A user account allows one to authenticate to system services. It also generally provides one with the opportunity to be authorized to access them. However, authentication does not automatically imply authorization. Once the user has logged on, the operating system will often use an identifier such as an integer to refer to them, rather than their username. On Unix systems this is called the user identifier or user id.

Computer systems are divided into two groups based on what kind of users they have:

• single-user systems do not have a concept of several user accounts
• multi-user systems have such a concept, and require users to identify themselves before using the system.

See also

• Nickname
• Password
• Moniker