In photography, contrast values describe the perceived difference between the light areas (highlights) and dark areas (shadows) within a scene. The range of these tonal differences, from the brightest highlights to the deepest shadows, determines the overall visual impact and depth of the image. High contrast values create striking, dramatic images with strong separation between light and dark, while low contrast values produce softer, more subtle transitions. Understanding contrast values is essential for photographers when capturing, developing, or printing images, as it allows control over mood, texture, and tonal balance in both film and digital photography.