Binocular disparity refers to the slight difference in the images received by each eye due to their horizontal separation. Each eye views an object from a slightly different angle, creating two distinct images. The brain processes these images to perceive depth and distance, allowing us to see the world in three dimensions. This phenomenon is crucial for depth perception, enabling us to judge how far away objects are. When the brain combines the two images, it can detect the disparity between them, which helps in understanding spatial relationships in our environment.