On Apple keyboards, a modifier key that is pressed with a letter or digit key to command the computer. For example, holding down the Option key and pressing left or right arrow moves the cursor to the previous or next word. Option is also used to enter copyright, trademark, math and other special symbols as well as accented letters for non-English alphabets. See
Command key and
Control key.
Mac Modifiers
The Option, Control and Command keys (Apple key) are the three modifier keys on Mac keyboards.