What is UI Design?

The simplest way to think about User Interface (UI) Design it is to think of it as the design of all the elements that users interact with on a screen. Think of all the Buttons, Labels, Text Fields, Controls, Switches, Sliders etc and then the layout of them.

Taking a button as an example, important things to consider in UI Design are:

• Usability: Does it look like I can press or tap it?
• Look and Feel: What colour is it? Is it a simple flat colour or does it have texture and style applied to it?
• State: What does it look like on hover, pressed and disabled states?

Consistency is important (you don't want users to constantly guess what is a button on each screen) so usually this involves creating a Design System to ensure this.