The document provides brief descriptions of common keyboard keys: 1) The Ctrl key is used in combination with other keys to perform commands. The Shift key allows for faster typing of numbers with one hand. The Caps Lock key turns capital letters on and off. 2) The Tab key moves the cursor to the next tab stop. The Backspace key cancels commands or a series of commands. 3) The Escape key cancels the current operation or returns to a previous setting.