The brake servo is a powered mechanism that reduces the amount of force you need to apply when braking. We've developed a two-stage brake servo with a highly sensitive response. Up to a brake pressure of about 45 bar, known as the comfort braking range, the braking force is boosted 5-fold. If you press the brake pedal more forcefully, the braking force is boosted by up to a factor of 10. You'll notice this by the fast braking response combined with short pedal travel, a good progressive brake modulation and reduced braking effort up to the point at which the ABS is activated.
Article source: www.volkswagen.co.uk