4.1.4 Switch between virtual console
In the default Debian system, there are six independent pseudo-terminals
available, i.e., you can use the PC's VGA character console screen as 6
switchable VT-100 terminals. Switch from one to another by pressing the
Left-Alt-key and one of the F1–F6 keys simultaneously. Each
pseudo-terminal allows independent login to accounts. The multiuser
environment is a great Unix feature, and very addictive.
If you accidentally typed Alt-F7 on a system running the X Window System and
the console screen displays graphic screen, regain the access to the character
console by pressing Ctrl-Alt-F1. Just try to move to different console and
come back to the original one to get used to this.