ELI5: What are CCFLs (cold cathode fluorescent lamps) in TV?

Imagine your TV screen is like a coloring book page. You see the pretty pictures, but the page itself doesn't glow. It needs light behind it to make the colors pop.

CCFLs (Cold Cathode Fluorescent Lamps) are like tiny, skinny light tubes used to shine light behind the screen of some older TVs. They're like the fluorescent lights you might have in your kitchen, but much smaller.

Here's how it works, simply:

• Think of the TV screen as having layers. The very front layer shows the pictures you watch.
• Behind that layer is a light source. In older TVs, that light source was often CCFLs.
• CCFLs are long, thin glass tubes filled with a special gas.
• When electricity flows through the gas, it makes the gas glow, producing a white light.
• This white light shines through the picture layer, making the colors look bright and vibrant.

Why don't TVs use them as much anymore?

• CCFLs can be bulky, making TVs thicker.
• They use more electricity than newer types of lights, like LEDs.
• They contain a tiny amount of mercury, which isn't great for the environment.