UI vs UX
In web and app design, some of the most commonly used words are UX (User Experience) and UI (User Interface). These are two confusing terminologies that most people think they are the same, but they are not.
UX stands for user experience, it involves the way that users interact with an application. The experience might be smooth, positive, confusing or intuitive. It might also involve whether the application feels arbitrary or logical. User experience mostly focuses on whether the user feels that the app is helping them accomplish the objectives they want to achieve efficiently, or they are just struggling.
UI stands for user interface, it refers to the graphical layout of an app. Normally it is comprised of buttons that the end-user of the app click, text they read, sliders, images and input fields, UI also includes other items such as interface animations, screen layouts, transitions and micro-interaction users usually interact with.