Unix has several control-key commands, that is, commands you enter by holding down the control key ctrl while simultaneously striking a second key. For example, you can backspace by holding down the control key and h key at the same time; this is denoted as ctrl-h, or in some documents as ^ h. These commands are important and powerful, yet also can be confusing and file annihilating, so be careful! For example, using ctrl-h and ctrl-u hardly ever do too much harm, yet locking up your terminal with ctrl-s or signing off the computer with ctrl-d hardly ever leads to smiles.
^ h
^ d
^ w
^ u
^ r
^ s
^ q
^ c
^ z