Complex sentence: The brake caliper pistons then apply force to the brake pads, which pushes them against the spinning rotor, and the friction between the pads and the rotor causes a braking torque to be generated, slowing the vehicle.
Split into simpler sentences: The brake caliper pistons then apply force to the brake pads. This causes them to be pushed against the spinning rotor, and the friction between the pads and the rotor causes a braking torque to be generated, slowing the vehicle.