Generally, aspect ratio is used to determine the proportional relationship between the vertical and horizontal sizes of computer graphics. Aspect ratio is represented by the symbolic notation: X:Y. The values of X and Y are not the real width and height of the image, but describe the proportional relationship between them. For instance, usually movies are shot with a wide-angle lens, typically have an aspect ratio that is 16:9. That means, the width of the image area is almost double of its height.