Is it possible to take a video screenshot (screenshow?) of what's occurring on a Macbook Pro's screen? I've got an unusual situation which I cannot explain. I thought to take a video of what I'm seeing on the screen, but realized I didn't know how to do that.

Is there a way to take a video of the screen's activities? From terminal, shortcut keys, or another method?
You can use QuickTime Player.app for this. Open it and in File menu there's New Screen Recording or press ⌃+⌘+N.