The significance of user interface design in applications lies in its impact on user experience and accessibility. A well-designed interface facilitates efficient interaction between users and the software, making it easy to navigate and accomplish tasks. By prioritizing usability, clarity, and aesthetic appeal, UI design enhances user satisfaction and engagement, leading to increased adoption and retention rates. Good UI design considers various factors, such as responsiveness, accessibility, and visual hierarchy, ensuring that the application caters to diverse user needs and preferences. Ultimately, effective interface design contributes to the overall success of digital products.