An aspect ratio is a relationship between the width and height of the image. It is usually shown in this format (W:H) where W is the width of the image and H is the height of the image. For example 4:3 aspect ratio means 4 units is the width and 3 units is the height of the image. The aspect ratios are important because it describes relationship between the main subjects to the sides of the frames and the amount of empty space left around the subject. In today’s world, there are many devices with different aspect ratios so it is important to display your product setting at a certain aspect ratio to make the most of the devices out there.