What is an app interface?
An application interface, or user interface, is the set of features an application provides so that a user may supply input to and receive output from the program. If you think about Microsoft Word as an example, the application interface includes a central area for typing and adding feedback on your screen.
What is an example of a user interface?
Put simply, a user interface is the point of human-computer interaction and communication on a device, webpage, or app. This can include display screens, keyboards, a mouse, and the appearance of a desktop.