No, a UI (user interface) designer is not necessarily a developer. UI design is a distinct discipline within the field of web and software development that focuses on the design of the graphical user interface and the user experience.
UI designers are responsible for creating the look and feel of a digital product, including the layout, typography, colour palette, and visual elements such as buttons, icons, and images. They use tools like Figma, Sketch, Photoshop, or Illustrator to create design mockups and prototypes, which are then used by developers to build the final product.
On the other hand, developers are responsible for building and implementing the functionalities of a digital product. They use programming languages like HTML, CSS, and JavaScript to create the interactive elements of a website or application and ensure that it works as intended.
While there is some overlap between UI design and development, they are generally considered separate disciplines with different skill sets and responsibilities. Some individuals may have both UI design and development skills, but these are still considered distinct areas of expertise.