A UI (User Interface) deals with the application's graphical layout, which includes buttons, screen layout, animations, transitions, micro-interactions, and so on. In short, UI is all about how things look.
UX (User Experience) design deals with how users interact with the system. Logical navigation and how smooth and intuitive the experience is all fall under UX design. In short, this type of design helps users have a positive experience.
UI designers earn an average of 50k worldwide, with the average salary in the USA being 91k, Germany being 57k, France being 47k, and 67k in the UK.
UX designers earn slightly more, with an average of 52k worldwide. UX designers in the US earn 102k on average, with Germany paying 53k, 49k in France, and 68k in the UK.