The Output Windows are a set of tabbed output windows, such as the Messages window (which displays messages like validation results), the Find in Files window, and the XPath window (which shows XPath evaluation results). The initial setting is for them to open at below the Main Window. The Output Windows command lets you switch the Output Windows on or off. If you close an individual Output Window, clicking the Output Windows command brings back the closed window.
Output Windows are dockable. Dragging on the title bar or tab of an Output Window detaches it from its current position and makes it a floating window. Right-click the title bar or tab to allow docking or to hide the window.
See the section Output Windows for a description of individual Output Windows.