# Graphical User Interfaces

Interface Windows |

An interface window is an area that is under the control of your application when running in a graphical operating system. Within a typical "windowing" environment, there can be a variety of window types, each displaying certain characteristics with a unique purpose for interacting with your application. The PxPlus syntax for implementing the different window formats is covered in this section.

There are as many ways to invoke a PxPlus graphical user interface application as there are windowing formats. One key rule to remember about creating a PxPlus graphical user interface is that PxPlus must be running in order to execute the application - that includes the primary application window (whether inside or outside the PxPlus console).

#### Note:
For information on creating the objects that make up the contents of an interface window, see Control Objects and Display Objects.

## Window Categories

In this documentation, the terms "panel", "dialogue" and "form" may be used to identify the functionality of different interface windows. While each windowing environment has its own rules and terminology, PxPlus window types generally fall within the categories described in this section.