A UI Framework is a collection of pre-written code and tools that help developers create user interfaces for applications more efficiently. These frameworks provide a structured way to build the visual components of software, such as buttons, forms, and menus, allowing developers to focus on functionality rather than starting from scratch. Popular examples of UI frameworks include React, Angular, and Vue.js. Using a UI Framework can significantly speed up the development process by offering reusable components and standardized design patterns. This not only enhances productivity but also ensures consistency in the look and feel of the application. Additionally, many frameworks come with built-in features for responsiveness, making it easier to create applications that work well on various devices.