How does the Audi e-Tron brake energy regeneration system work?

I am considering purchasing an Audi e-Tron and I know that it uses brake energy regeneration. Could you explain how this technology works and how effective it is in real-world driving situations?

The Audi e-Tron uses a system called 'electromechanical brake booster' which allows the car to capture kinetic energy during braking and convert it into electricity. This is then stored in the battery for later use. This technology has been shown to be quite effective, with some drivers reporting an increase in range of up to 15%.