A mobile user interface (UI) refers to the design and layout of elements that allow users to interact with a mobile device. It encompasses the visual components such as buttons, icons, menus, and text fields, along with the overall structure of screens and navigation flows. A mobile UI is optimized for touch interactions, featuring intuitive gestures like swiping, tapping, and pinching. The goal is to create a seamless, user-friendly experience by ensuring accessibility, efficiency, and responsiveness across different mobile devices and screen sizes. A well-designed UI enhances usability and promotes positive user engagement with the app or system.