Modifier Key

A key on a keyboard that modifies the action of another key when both are pressed simultaneously, such as Shift, Control (Ctrl), Alt, Option, or Command. Modifier keys present a significant accessibility barrier for users who can type with only one hand or who have difficulty pressing two keys at the same time due to motor impairments. The Sticky Keys accessibility feature addresses this barrier by allowing modifier keys to be pressed and released sequentially rather than held simultaneously.