How many braking systems a vehicle should have 4 or 5?

Normally, a vehicle has ONE braking system that includes the brake pedal, the brake master cylinder, newer cars then have the Anti-Lock Braking System, then there are either disc type or drum type brakes at each wheel, and everything is connected with small metal and rubber hoses that allow the pressurized brake fluid to activate the brake pads and/or brake shoes that cause the friction necessary to slow your vehicle.