Switching between graphical and text mode

GNU/Linux is configured by default to have 7 virtual consoles, with X Window running on the seventh (when it is running).

Switching from X Window to one of the 6 consoles: Ctrl + Alt + F1, ..., Ctrl + Alt + F6.

Switching from a text console to another text console: Alt + F1, ..., Alt + F6.

Switching back to X Window: Alt + F7.