Television aspect ratio refers to the screens width compared to its height. Traditional television aspect ratio is 4×3. For example, a 32-inch traditional television screens would be 25 1/2 inches wide and 19 inches tall. Widescreen aspect ratio is 16×9. A 32-inch widescreen television screen would be 28 inches wide and 19 inches tall.
(Adapted from www.dtv.gov)