Speed sensors are devices that measure the speed of a moving object, often used in vehicles to monitor how fast they are traveling. These sensors can be found in various forms, such as wheel speed sensors and GPS speed sensors, each providing important data for vehicle performance and safety systems. In cars, speed sensors help the engine control unit (ECU) adjust fuel injection and transmission settings for optimal performance. They also play a crucial role in anti-lock braking systems (ABS) by preventing wheel lock-up during braking, enhancing overall vehicle stability and control.