Here's a breakdown of its key components and how it works:

Infrared Emitter and Receiver: The module typically contains an IR emitter (often an IR LED) and an IR receiver (usually a photodiode or phototransistor). The emitter emits infrared light, and the receiver detects the reflected infrared light.

Active Low Output: "Active Low" means that the sensor's output signal goes low (or near 0V) when it detects an obstacle. In other words, the sensor's output is normally high (at a higher voltage level) and drops to a lower voltage level when an obstacle is detected.

Obstacle Detection: When there's no obstacle in the sensor's line of sight, the IR light emitted by the emitter isn't reflected back to the receiver, so the receiver's output remains high. However, when an obstacle or object is present in front of the sensor, it reflects the IR light back to the receiver, causing the receiver's output to go low.

Digital Output: The output of this type of sensor is typically digital, making it easy to interface with microcontrollers or other digital electronics. You can connect the sensor's output pin to a microcontroller's digital input pin to detect obstacles and trigger appropriate actions.