What is the rain sensor used for on the Audi A5?

I've noticed a rain sensor on the windshield of my Audi A5. What is its purpose and how does it work?

The rain sensor is used to detect the amount and intensity of rain and automatically adjusts your windshield wipers accordingly.

It uses infrared light to measure the reflections off the windshield and determine the amount of water on the glass, triggering the wipers to turn on or adjust speed.

It also helps to reduce driver distraction by automatically activating the wipers, so you can focus on the road.