UI stand for User interface which is a broad term for any system either physical or software based that allows a user to connect with a given technology. Many different kinds of UI come with various devices and software programs. Many of them have some basic similarities, although each one is unique in key ways. In information technology, the UI is everything designed into an information device with which a human being may interact including display screen, keyboard, mouse, light pen, the appearance of a desktop, illuminated characters, help messages, and how an application program or a Web site invites interaction and responds to it. In early computers, there was very little user interface except for a few buttons at an operator's console. The user interface was largely in the form of punched card input and report output.