The Window menu deals with the layout of the different windows, and their visibility.

□ Audio/MIDI SetupShows the Audio/MIDI Setup window, where the sound system configuration can be modified
Editor
Show EditorSwitches to the Editor view
HideHides the Editor, hence showing the Mixer when the windows are attached
AttachIf the Editor window is detached, separated from the main window, attach it back
DetachIf the Editor is attached to the main window, detach it (makes the Editor a separated window, useful for multi-monitor setup)
Mixer
Show Mixer/Hide/Attach/DetachSame as for the Editor, for the Mixer window
Preferences
Show/Hide/Attach/DetachSame as for the Editor, for the Preferences window
MeterbridgeShows the Meterbridge window, that displays all the tracks' meter at once and their recording status, and is very handy for multitrack recording
□ Tracks and BussesOpens the Tracks and Busses window, which is a shortcut to many tracks/busses operations (routing, effects, …)
□ LocationsOpens the Ranges and Marks window, a single point of control for all range and location markers
□ Bundle ManagerOpens the Bundle Manager window, allowing to create and manage Bundles, which are a way to simplify connection management, by defining groups of ports
□ Big ClockOpens the Main Clock as its own separate (and huge) window, which is helpful when recording
□ Transport ControlsOpens a floating Transport Bar as its own separate window
□ Transport MastersOpens the Transport masters window, where all the timecode sources are shown to be selected and/or synchronized
□ Plugin DSP LoadOpens a window showing all the active effects, plugins, etc… with bar-graphs showing the induced DSP load latency
□ Video MonitorIf a video has been imported in the session, opens a video window (namely, Xjadeo), synced to the timeline
□ Audio ConnectionsOpens the Audio Connection Manager window, a way to make connections to, from and within Ardour's mixer
□ MIDI ConnectionsSame as above, for the MIDI connections
ScriptingOpens the Script console window where LUA scripts can be edited and run
TemplatesOpens the Template Manager window, for both sessions and tracks templates managment
□ Keyboard ShortcutsOpens up a Keyboard Shortcuts window, which allows for easy creation or modification of any keyboard binding
□ Virtual KeyboardOpens up a virtual MIDI keyboard. If a MIDI track is selected (or many), this keyboard can be used to play, record or affect the selected track(s) or automation as an hardware device would.
Midi TracerOpens the MIDI Tracer window, allowing to follow each and every MIDI message entering or leaving Ardour
□ LogShows the Log window, where Ardour lists useful information, warnings and errors