When someone knocks on your office door, you may have a sensitive email or student work on your screen. Rather than figuring out if what is on your screen can be safely seen, use a keyboard shortcut to minimize everything so only your desktop shows.
Windows key + D (“D” is for desktop).
When your visitor leaves, that same key combination will bring back everything where it was.
Command + F3 (“F3” is for F3).
When your visitor leaves, that same key combination or just F3 will bring back everything where it was.