Many computer functions depend on user interaction, either ongoing or to get things started. In order to interact with programs and displays on a computer, users may use a keyboard or use a pointing device. The most often used pointing devices include the computer mouse, the joystick, the trackball, the light pen, the stylus and graphics tablet, the touch screen, the touchpad or trackpad, and the pointing stick. The Wii® remote, which works only with the Nintendo® Wii® console, may be considered a special type of pointing device.
Some kind of mouse is probably the most widely-used computer pointing device. A mouse is a small, oval-shaped device that one rests one’s hand on and slides around to move the on-screen pointer. Mice have built in clicking action to interact with the display, and some have a scroll and multiple programmable buttons. There are different types of mice including wireless mice, USB mice, mini-mice, ergonomic mice, and the footmouse, which is operated with the foot, rather than the hand.
A joystick is a lever that points at the ceiling and tilts in all directions. The pointer moves in the direction the joystick is pointed until it is returned to the upright position. Joysticks are most often equipped with triggers in the form of buttons. The trackball, on the other hand, is a pointing device that is rolled in the direction(s) in which the user wants the pointer to move. Some trackballs have a scroll wheel and mouselike buttons on their device.
A graphics tablet is a type of pointing device that may be controlled by a stylus held like a pen, a mouse, or either one interchangeably. The stylus may have a button, and the tablet itself may have buttons and a scroll. It is popular with graphic designers, photographers, and other artists. The touch screen is also used by artists with a stylus as the interactive tool. Other types of touch screens use finger movement.
The touchpad or trackpad and the pointing stick are pointing devices built into laptop computers. The touchpad is a rectangular surface across which one can move one’s finger, as well as click and double-click with it. The pointing stick is a very small, pressure-sensitive nub on some lap top models and used similarly to the way a joystick is used.