UI/UX Design is the process of designing the interface, optimizing navigation, and showing relevant features of a product or service with the focus on maximizing usability and the user experience.
UI stands for User Interface referring to the screens, buttons, toggles, icons, and other visual elements that you interact with when using a website, app, or other electronic devices. UX stands for user experience that allows you to interact with a product, including how you feel about the interaction. Both these aspects are intertwined to produce the desired results.