User interface (UI) design significantly affects user experience (UX) as it encompasses the aesthetics and functionality of an application. An intuitive UI facilitates seamless interactions, ensuring users can navigate the application easily and efficiently. Effective UI design incorporates principles of usability, accessibility, and visual hierarchy, which are crucial for enhancing user satisfaction. A well-designed UI promotes positive engagement and reduces user frustration, encouraging repeat usage. Conversely, poor UI can lead to confusion and abandonment. Therefore, prioritizing UI design is essential for businesses looking to optimize user experience and achieve their goals.