A sodium vapor lamp is a type of gas discharge lamp that produces light by passing an electric current through vaporized sodium. These lamps are known for their bright yellow-orange light and are commonly used for street lighting and outdoor illumination. They are efficient and have a long lifespan, making them a popular choice for public lighting. The lamp operates by heating sodium metal until it vaporizes, which then emits light when energized. There are two main types: low-pressure and high-pressure sodium vapor lamps. Low-pressure lamps emit a softer light, while high-pressure lamps provide a brighter, more intense illumination.