An Infrared (IR) sensor module is used to detect the difference between black and white surfaces. It works by emitting infrared light through an LED and measuring the reflected signal with a photodiode. A white surface reflects IR light strongly, while a black surface absorbs it, creating different voltage outputs. In the Line Following Robot, these sensors are mounted at the bottom of the chassis to detect the path. Depending on the reflection received, the Arduino decides whether to move forward, turn left, or right. Multiple IR sensors improve accuracy, making the robot follow the track smoothly.