Phase Detection Autofocus is a technology used in cameras to quickly and accurately focus on subjects. It works by splitting incoming light into two beams and comparing their phase differences. This allows the camera to determine whether the subject is in focus or needs adjustment, enabling faster focusing than other methods. This system is commonly found in DSLR cameras and some mirrorless models. It excels in bright conditions and is particularly effective for tracking moving subjects, making it a popular choice for sports and wildlife photography.