Computer Pointing and Input Peripheral Devices

This group gathers hand-operated peripheral devices built to let a computer user direct an on-screen cursor, enter drawing and positional input, or control a program, as distinct from the display and storage hardware inside the machine itself. Members include the computer mouse, whose two-dimensional motion across a surface is translated into cursor movement, the trackball, which inverts the same principle by having the user roll an exposed ball housed in a fixed base, the touchpad, which senses a fingertip's position and motion directly on a flat sensing surface, the joystick, which reports the angle of a pivoting stick to the device it controls, and the graphics tablet, which lets an artist or drafter hand-draw or trace an image using a stylus. The computer keyboard, adapted from the typewriter's arrangement of mechanical or electronic keys, anchors the group as its most universal and longest-established member.