When the brake light on your car's dashboard comes on, it is a warning that there is a potential problem with your vehicle's braking system. This light can indicate several issues, including:

• Low brake fluid level in the reservoir, which is critical for hydraulic brake function.
• The emergency (parking) brake is engaged or not fully released.
• A fault or failure in the Anti-lock Braking System (ABS), such as sensor or electrical problems.
• Worn or damaged brake pads that need replacement.
• Hydraulic brake circuit failure or other sensor malfunctions.

The brake warning light is different from the external brake tail lights, which simply illuminate when you press the brake pedal to signal other drivers. If the brake light comes on while driving but the brakes feel normal and fluid levels are adequate, it could be a sensor fault, but you should still have the brakes inspected promptly. If you notice reduced braking performance, the light flashes, or you feel unsafe, you should safely pull over and seek assistance immediately. Continuing to drive with a brake warning light on can be dangerous and may cause further damage to the braking system

. In summary, the brake light means your car is alerting you to a braking system issue that requires timely attention to ensure your safety and proper vehicle function.