Windows are used to display content and to combine content produced by different renderers. Each of the different renderers can be in the same process, or in another process or processes.

The concept of a window in Screen differs slightly from what you're probably used to in a traditional windowing system. In Screen, applications are split into several windows when content comes from different sources, when one or more parts of the application must be updated independently from others, or when the application tries to target multiple displays. For example, a user interface that was developed in Adobe AIR can be overlaid on top of a native document viewer, or a plug-in can be embedded within a web view or document. Adobe AIR components can be used to form user interface controls for navigation or media playback. These controls can be contained within a window that is overlaid over top of a map or multimedia. In this example, the background window must be updated independently from the foreground user interface controls.