Analysis of information sources in references of the Wikipedia article "Light gun" in English language version.
Light guns, such as the NES Zapper or those used in the House of the Dead series, are distinctly different from positional guns used by arcade games such as SEGA's Gunblade NY. ... Light guns differ from positional guns, such as in Gunblade NY (bottom), that are essentially analog joysticks. ... Positional guns are essentially analog sticks mounted in a fixed location with respect to the screen. Light guns, in contrast, have no fixed a priori relationship with a display.
The two routes to conventional gun control are light guns and positional guns. Light guns are the most common for video game systems of any type. They work optically with screen and do not keep track of location on the screen until the gun is fired. When the gun is fired, the screen blanks for a moment, and the optics in the gun register where on the screen the gun is aimed. That information is sent to the computer, which registers the shot. ... Positional guns are mounted stationary on the arcade cabinet with the ability to aim left/right and up/down. They function much like joysticks, which maintain a known location on screen at all times and register the current location when fired.