A neon sign is a type of illuminated sign that uses neon gas-discharge tubes to create bright, eye-catching displays. The tubes are filled with neon gas and an electrical current is applied, causing the gas to emit light. The light produced by neon signs can be seen in a wide range of colors, including red, green, blue, yellow, and pink, among others. Neon signs are often used for commercial advertising, decorative purposes, and as works of art. They are durable, long-lasting, and energy-efficient, making them a popular choice for many applications.