1.1. User Interface versus Graphical User Interface

Introduction

If you click on an arbitrary button (pdf, glossary or help button, etc.) or interactive item (interactive index, link, etc.) while reading this lesson, you interact with the computer system.

When you sit in front of the screen of a running computer, you always face a User Interface (UI). As the name implies, a User Interface is an interface between the user and the computer. The first user interfaces were command-line interfaces where you only could interact with the computer by typing commands on the keyboard (some Unix users still use this kind of interface). Today, we (Mac, Linux and Windows-Users) expect to interact with the computer using a mouse, launching programs by clicking on icons, and manipulate various windows on the screen using graphical controls. Such user interfaces are called Graphical User Interfaces (GUI), since they use graphics and pictures to represent the input and output of a program.

GUI (screenshot © Quantum GIS)