A UI Framework is a collection of pre-designed components and tools that help developers create user interfaces for applications. It provides a structured way to build the visual elements of software, such as buttons, forms, and navigation menus, ensuring consistency and efficiency in design. Popular examples of UI frameworks include React, Angular, and Bootstrap. These frameworks often come with built-in styles and functionalities, allowing developers to focus on the logic of their applications rather than starting from scratch. By using a UI framework, teams can streamline their development process, improve collaboration, and enhance the overall user experience of their products.