Aspect ratio

Aspect ratio of a shape is the ratio between width and height. For example, if a picture or video has the High Definition resolution of 1920x1080, that means the width is 1920 and the height is 1080. If we write them as aspect ratio, these two parameters become (width:height) 16:9. Dividing both of them by the lowest common denominator 120 it becomes 16:9 with allways the result of 1.777... This is ultimately the aspect ratio of the shape. Similar calculations apply to other shapes, such as buildings, flags, wings, or sheets of paper or other material.

So, the narrow aspect ratio is up to 4:3 (also called 1.333... and the standard aspect ratio for digital photography) and the wide aspect ratio is beyond 4:3.

 References 

Category:Display technology