What is UI Design?

The “UI” in UI design stands for “user interface.” The user interface is the graphical layout of an application. It consists of the buttons users click on, the text they read, the images, sliders, text entry fields, and all the rest of the items the user interacts with. This includes screen layout, transitions, interface animations and every single micro-interaction. Any sort of visual element, interaction, or animation must all be designed.
UI designers are graphic designers. They’re concerned with aesthetics. It’s up to them to make sure the application’s interface is attractive, visually-stimulating and themed appropriately to match the purpose and/or personality of the app. And they need to make sure every single visual element feels united, both aesthetically, and in purpose.

“UX” stands for “user experience.”User experience is determined by how easy or difficult it is to interact with the user interface elements that the UI designers have created.
So UX designers are also concerned with an application’s user interface, and this is why people get confused about the difference between the two. But whereas UI designers are tasked with deciding how the user interface will look, UX designers are in charge of determining how the user interface operates.