The proportional relationship between the width and height of a photographic image or print. It defines the shape of the frame and affects composition and cropping. For example, 35mm photographs typically have an aspect ratio of 2:3, resulting in common print sizes of 3.5 x 5 inches or 4 x 6 inches. Understanding aspect ratio is important for framing, enlarging, and displaying images, as well as for matching prints to standard frames or digital displays without distortion.