The Settings window can be opened through the Windows menu (Windows >> Settings) or using the Ctrl+E shortcut.
The Settings Window is comprised of several pages described in separate subsections and accessible via the Settings menu:
The page opened at any given time is indicated in the Window's title bar (for instance, the General Settings page is shown in the picture above).
The Settings window can remain opened or be closed at any time. The settings defined through the Settings window take effect immediately throughout the program.
Reciprocally, any setting modified in the main window will be reflected in the Settings window.