One of the common ways of producing light in a theater, most commonly found in high end moving lights. When the right amount of electricity is sent through a gas, the molecules begin to vibrate. As they vibrate they give off light. Each type of gas gives off a different color of light. Neon for example glows reddish orange. By mixing gases in different combinations, a wide variety of colors can be created, including an intense white light. A discharge lamp is quite simple in operation, it includes an envelope of gas with two electrodes. As electricity jumps the gap between electrodes it excites the gas around it and causes light to be created. This is why discharge lamps require warm up time. Also known as an arc lamp, not to be confused with carbon-arc. Carbon arc is one of many subsets of discharge (arc) sources. Other types include Xenon, HMI, HID, metal-halide, MSR/MSD, and sodium-vapor.