In computer graphics, the relative horizontal and vertical sizes. For example, if a graphic has an aspect ratio of 2:1, it means that the width is twice as large as the height. When resizing graphics, it is important to maintain the aspect ratio to avoid stretching the graphic out of proportion.
The term is also used to describe the dimensions of a display resolution. For example, a resolution of 800x600 has an aspect ratio of 4:3.