The relationship of width to height of a screen and can be expressed as a ratio such as 4:3 or as a whole number 1.33. Our old NTSC system was designed for 4:3 where 4 is the width and 3 is the height. If you divide 3 into 4 you get the whole number expression of 1.33 where you take the height of your screen times 1.33 to find the width.
HDTV and most DVD is 16:9 or 1.78 increasing the width of the screen.
HDTV and most DVD is 16:9 or 1.78 increasing the width of the screen.