1. **Electronic Control Unit (ECU):** - The ECU is the brain of the anti-theft system, managing and processing signals from various sensors and ensuring that the vehicle can only be started by authorized users. 2. **Immobilizer:** - This system prevents the engine from starting unless the correct key or fob is used. It typically uses a transponder chip in the key that communicates with the car's ECU. 3. **Alarm System:** - Alarms are triggered if unauthorized access is detected, such as a door being opened without the correct key or an attempt to start the car without authorization. Modern alarms may include sensors for motion, glass breakage, or tilting. 4. **Keyless Entry and Ignition Systems:** - These systems use key fobs that transmit signals to the car to unlock doors or start the engine without the need to physically insert a key. 5. **Steering Wheel Locks:** - A mechanical device that locks the steering wheel in place, making it difficult to steer the car without the correct key. 6. **Tracking Systems:** - Some advanced anti-theft systems include GPS tracking, allowing the vehicle to be located if stolen.