What type of light bulb is commonly used in advertising sings and decorations?

LED bulbs are commonly used in advertising signs and decorations due to their energy efficiency, long lifespan, and vibrant color options. Neon lights, which create a bright glow in various colors, are also popular for their eye-catching effect. Additionally, incandescent bulbs can be used for a classic look in retro-style signage. Overall, the choice often depends on the desired aesthetic and functionality.