Quick meaning
Everything you can see and interact with on a screen — buttons, menus, colours, and layouts.
Think of it like this
Like the dashboard and controls of a car — what you see and touch to operate the system.
Where you may see this
You may see this inside app stores, app settings, software updates, and install instructions.
Why it matters
Knowing the term helps you understand what an app is asking you to do before you tap, install, or change anything.
Say it simply
UI (User Interface) means: Everything you can see and interact with on a screen — buttons, menus, colours, and layouts.