What is the main function of a brake booster in a typical automotive braking system?

The main function of a brake booster in a typical automotive braking system is to assist the driver in applying the brakes by increasing the force of the braking effort. This is achieved by using hydraulic pressure or vacuum to amplify the force applied by the driver on the brake pedal. This makes it easier for the driver to apply the brakes and brings the vehicle to a stop more effectively and efficiently.