To use a keyboard shortcut, or key combination, you press a modifier key with a character key. For example, pressing the Command key (the key with a symbol) and the "c" key at the same time copies whatever is currently selected (text, graphics, and so forth) into the Clipboard. This is also known as the Command-C key combination (or keyboard shortcut). A modifier key is a part of many key combinations. A modifier key alters the way other keystrokes or mouse clicks are interpreted by Mac OS X. Modifier keys include: Command, Control, Option, Shift, Caps Lock, and the fn key (if your keyboard has a fn key). Here are the modifier key symbols you can see in Mac OS X menus: (Command key) - On some Apple keyboards, this key also has an Apple logo ( ) (Control key) ( Option key ) - "Alt" may also appear on this key (Shift key) (Caps Lock) - Toggles Caps Lock on or off fn (Function key) Startup keyboard shortcuts Press the key or key combinatio...