Do you prefer an 4:3 TV or an 16:9 TV?
Don't worry, both of them are HD.
Notes & Credits
You might be familliar with Aspect Ratio.
The most common ones are 4:3 (1.33:1), and 16:9 (1.7(7/8):1).
There are other Aspect Ratios but for now lets stick with this one.
