That quality of a system that makes it easy to learn, easy to use and encourages the user to regard the system as a positive help in getting the job done. User A person who uses a system to perform a business function.

In many circumstances in computer systems there may be alternate ways a user can influence the behavior of a utility, user interface, or other system process. Typically set by adjusting values in a set of user preferences; for example, in a program generator, preferences may be set for style, performance, user interface behavior and code standards.