There are several types of UI design, each with its own unique approach and focus. Here are some of the most common types of UI design:

1. Graphic design: This involves creating the visual elements of a user interface, such as color schemes, typography, and icons.
2. Interaction design: This focuses on how users interact with a product, including the design of buttons, menus, and other interactive elements.
3. Information architecture: This involves the organization and structure of information within a user interface, including the layout of screens and the navigation flow.
4. User research and testing: This involves conducting research on user needs and behaviors, as well as testing user interfaces with real users to identify issues and areas for improvement.
5. Usability design: This focuses on ensuring that a user interface is easy to use and intuitive, including designing for accessibility and ensuring that users can complete tasks efficiently.
6. Mobile design: This involves designing user interfaces specifically for mobile devices, taking into account factors such as screen size, touch controls, and mobile-specific user behaviors.
7. Web design: This focuses on designing user interfaces for websites, including considerations such as responsiveness, accessibility, and search engine optimization.

Overall, the type of UI design that is most appropriate for a given project will depend on factors such as the type of product being developed, the target audience, and the specific goals of the project.