" D-pad (short for directional pad) is a tetradirectional (4-direction) control found on nearly all modern video game console gamepads and game controllers, with one button on each point. Like early video game joysticks, the vast majority of D-pads are digital; in other words, only the directions provided on the D-pad buttons can be used, with no intermediate values. However, combinations of two directions (up and left, for example) do provide diagonals. Although digital D-pads offer less nuance and flexibility than analog sticks, they can easily be manipulated (requiring little movement of the thumb) with very high accuracy. In recent years, D-pads have been developed which can measure different levels of pressure, giving a degree of analog control. D-pads have appeared on other kinds of electronic equipment, including A/V remote controls (especially since the appearance of DVD players, which are heavily menu driven), calculators, and PDAs. In addition, full-sized computer keyboards often have cursor control keys arranged in a T or cross pattern for use as a D-pad; for older computer games, sometimes the I, J, K, and M keys (arranged in a cross shape on a QWERTY keyboard) serve the same function." http://en.wikipedia.org/wiki/D-pad

"A D-pad (short for directional pad) is a tetradirectional (4-direction) control found on nearly all modern video game console gamepads and game controllers, with one button on each point. Like early video game joysticks, the vast majority of D-pads are digital; in other words, only the directions provided on the D-pad buttons can be used, with no intermediate values. However, combinations of two directions (up and left, for example) do provide diagonals. Although digital D-pads offer less nuance and flexibility than analog sticks, they can easily be manipulated (requiring little movement of the thumb) with very high accuracy. In recent years, D-pads have been developed which can measure different levels of pressure, giving a degree of analog control. D-pads have appeared on other kinds of electronic equipment, including A/V remote controls (especially since the appearance of DVD players, which are heavily menu driven), calculators, and PDAs. In addition, full-sized computer keyboards often have cursor control keys arranged in a T or cross pattern for use as a D-pad; for older computer games, sometimes the I, J, K, and M keys (arranged in a cross shape on a QWERTY keyboard) serve the same function." http://en.wikipedia.org/wiki/D_pad