All the windows that are part of the GPS environment are under control of what is commonly called a multiple document interface (MDI for short). This is a common paradigm on windowing systems, where related windows are put into a bigger window which is itself under control of the system or the windows manager.
This means that, by default, no matter how many editors, browsers, views, ... windows you have opened, your system will still see only one window (On Windows systems, the task bar shows only one icon). However, you can organize the GPS windows exactly the way you want, all inside the GPS main window.
This section will show the various capacities that GPS provides to help you organize your workspace.