User interfaces (UI) refer to the means by which users interact with a computer or device. This can include graphical user interfaces (GUIs), command-line interfaces, touchscreens, and more. UI research focuses on designing and developing interfaces that are intuitive, efficient, and user-friendly, taking into account factors such as user experience, accessibility, usability, and aesthetics. Researchers in this area also study how users interact with interfaces, conduct usability testing, and explore new technologies such as augmented reality and voice-controlled interfaces. The goal of UI research is to create interfaces that enhance the user's overall experience and make interacting with technology more seamless and enjoyable.