What is regenerative braking and how does it work?

I've heard that the Audi e-Tron has regenerative braking, but I'm not sure what that means. Can someone explain it to me?

Regenerative braking is a feature in most electric cars, the e-Tron included, that captures the kinetic energy generated by braking and stores it in the battery. This not only increases the range of the car, but also reduces wear and tear on the brake pads.

Think of it as a way to charge your car while you're driving. Every time you press the brake pedal, the car converts the energy of motion into electricity and sends it back to the battery.