A user interface (UI) is the point in which a user and a machine interact and typically refers to input devices and software. There are many different types of user interfaces designed for a variety of uses. A user interface can be a computer mouse, a touch screen on a device, a remote control, a microphone, or even a speedometer. The term user interface can be applied to any means that allows users access to software internally and externally, or in other words, what makes human communication and control possible. An example of a user interface in the form of software, as opposed to an input device, would be the display of an app or website. As the demand for apps increases, so too does the development of user interfaces.
The user interface and user experience (UX) are what determine whether an app or device is deemed "user-friendly." The design of a UI determines how the product’s (device, webpage, or app) look and feel. UI design is not only responsible for aesthetics, but also responsiveness, efficiency, and accessibility of the user interface.
Early computers used punched cards, which were prepared using keypunch machines, as the primary method of input for computer programs and data, and there was very little user interface. With the introduction of the command line interface, which appeared as a nearly blank display screen with a line for user input, users had to rely on a keyboard and a set of commands to control and exchange information on a computer. This command line interface evolved into menu-driven user interfaces between the 1960s and 1980s.
The more familiar Graphic UI arrived in the 1970s, which utilized icons and visual metaphors to aid human-computer interaction. GUI is often attributed to Xerox's Palo Alto Research Center (PARC), and its continued early development is credited to Apple and Microsoft founders.
However, the initial GUI research and development began as early as 1945, with Vennevar Bush's idea of the "memex." The memex was a computing device that would use hyperlink technology to bring information to every users' fingertips. With the development of the mouse in 1962 by Douglas Engelbart, it became more feasible to navigate windows, menus, and links within a computer. Thus people began to develop graphic icons and displays to convey, transmit, and control information within computers.