User Interface (UI) refers to the space where interactions between humans and machines occur. It encompasses the design elements that allow users to navigate and control software applications or websites. UI includes buttons, icons, menus, and other visual components that facilitate user engagement and experience. A well-designed UI aims to make the user's experience intuitive and efficient. It focuses on usability, ensuring that users can easily understand how to interact with the system. Good UI design can significantly enhance user satisfaction and productivity, making it a crucial aspect of software development and digital product design.