n.The means by which a human communicates with hardware or a software application.
Notes'User interface' emphasizes design, rather than specific input/output devices. For example, a keyboard, mouse, and monitor may be parts of a user interface, but not an interface themselves. The command-line interface (CLI) is an example of a user interface, which often uses a character-based prompt displayed on a monitor, with information entered from a keyboard. The graphical user interface (GUI) may use icons displayed on a monitor, with actions performed by a mouse click.