How does the active rear spoiler work on the BMW M9?

I've heard that the BMW M9 has an active rear spoiler, but I'm not sure how it actually works. Can someone explain it to me?

The active rear spoiler on the BMW M9 uses a sophisticated algorithm to detect the car's speed and adjust accordingly. It deploys at higher speeds to provide increased downforce and stability, and retracts at lower speeds to reduce drag and improve fuel efficiency.

I've noticed that the active rear spoiler also deploys during hard braking to provide additional downforce and improve braking performance. It's a great feature to have on a performance car like the BMW M9.