Virtual Terminal 3. If you press Ctrl-Alt-F2 (forward arrow), you'll get to VT2. You can install crouton and run xinit, which will start a window manager in VT3 (Ctrl-Alt-F3/Reload).

I've got my setup scripted here:

https://github.com/appsforartists/pixel_webdev

I think he means this: https://en.wikipedia.org/wiki/Virtual_console