Gas discharge devices are electronic components that conduct electricity through a gas. When a voltage is applied, the gas becomes ionized, allowing current to flow. Common examples include neon lamps and fluorescent lights, which emit light when the gas inside is energized. These devices are used in various applications, from lighting to signaling. They can produce different colors of light depending on the type of gas used. Additionally, gas discharge devices are often found in plasma displays and gas lasers, showcasing their versatility in technology and entertainment.