User interface (UI) design is the process of designing the look, feel, and interactivity of a digital product, such as software or computerized devices, with the focus on maximizing usability and the user experience. UI design refers to graphical user interfaces and other forms of interface design, such as voice-controlled interfaces. It involves visualizing, grid typography, hierarchy, readability, and some basic aesthetics. UI designers aim to create interfaces that are easy to use and pleasurable, and they play a crucial role in shaping the users interaction with a digital product, impacting its success and usability.

UI design is different from user experience (UX) design, although the two are related. UX design covers the entire spectrum of the user experience, while UI design is more about the surface and overall look of a design. UX design focuses on satisfying user intent and providing a clear navigation path to access information on a site or app, while UI design focuses on interaction design, the visual elements of a website or application, and ensuring a navigation path is visually attractive and effortless to use.

UI design is a purely digital practice that considers all the visual, interactive elements of a product interface, including buttons, icons, spacing, typography, color schemes, and responsive design. A well-designed user interface is crucial to ensuring a good user experience.