Foreground detection is a computer vision technique used to identify and isolate the main objects or subjects in a video or image, distinguishing them from the background. This process is essential in various applications, such as surveillance, object tracking, and video editing, where understanding the primary focus of a scene is crucial. The technique typically involves analyzing changes in pixel values over time or using machine learning algorithms to recognize patterns. By effectively separating the foreground from the background, systems can enhance the quality of visual data and improve the accuracy of tasks like motion detection and scene understanding.