Gas discharge tubes are devices that allow electric current to flow through a gas, typically at low pressure. When a voltage is applied, the gas inside the tube becomes ionized, creating a conductive path. This process produces light and can be used for various applications, such as in neon signs or lightning arresters. These tubes come in different shapes and sizes, depending on their intended use. They are often made from glass and filled with gases like neon or argon. Gas discharge tubes are commonly used in electronics and lighting, providing a reliable way to manage electrical energy.