Many machines have been designed to interact with people in some way. And so the designer must think about how to make that interaction happen as easily and effortlessly as possible.

For example, a vending machine - you want a drink, but how do you get the machine to give it to you? You will have to go through a specific set of tasks - press the button, put in the money and eventually your drink will pop out (hopefully!).

You interact with the machine through its user interface.

A computer also has an 'user interface' in order to allow you to work with it. They can be classified into the following categories:

 

	Command driven.
	Menu driven.
	Form Driven.
	Graphical User Interface
	Natural Language

Each one has its merits and each also has its disadvantages. There is no perfect user interface.  

This web site will introduce you to types of user interface.