Short for user interface, this is where the user may interact with a computer or computer program.
The interface is a set of commands or menus which is typically command-driven, this is basically where the user is entering instructions.
Everything from a monitor, keyboard, to a mouse or light pen can be considered to be a UI, but typically it is the term now used when referring to the graphical user interface, or GUI.
Why are UIs constantly redesigned?
Standard Definition Exists?
The means by which the user and a computer system interact, in particular the use of input devices and software.