Contrast stretching is a technique used in image processing to enhance the contrast of an image. It works by expanding the range of intensity values in the image, making dark areas darker and light areas lighter. This helps to reveal details that may be hidden in the original image, improving overall visibility. The process involves identifying the minimum and maximum intensity values in the image and then mapping these values to a new range. By redistributing the pixel values, contrast stretching can make features more distinguishable, which is particularly useful in applications like medical imaging and satellite imagery analysis.